How to fix common Selenium errors?

by | Jul 26, 2016 | Selenium Problems | 36 comments

How to fix common Selenium errors?

How to debug your errors and be self sufficient?

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How can I ask you a question?

Provide me with a SSCCE question in the comments below. I respond daily.

A project with an output Type of class library cannot be started directly

Error Message

A project with an output Type of class library cannot be started directly. In order to debug this project, add an executable project to this solution which references the library project. Set the executable project as the startup project.

Project with an output type of class library

Project with an output type of class library

The Problem

The problem is that you create a project as a type “Class Library” or “Unit Test Project” and are attempting to execute this project using the key F5, which means “Run”. You cannot run these types of projects in this manner. A unit test project must be executed using the Test Explorer of Visual Studio.

The Solution

Option 1

In your IDE, go to Test > Windows > Test Explorer. This will open up the Test Explorer. Right click the name of your unit test and then select “Run Selected Tests”.

Option 2

Place the cursor inside of your test method. Press Ctrl + R, T. This will run the test that has the cursor.

This free C# course will teach you how to correctly run the different kinds of projects.

I fixed my #Selenium error using this post https://wp.me/p7absY-4E

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Program does not contain a static ‘Main’ method suitable for an entry point

Error Message

Program does not contain a static ‘Main’ method suitable for an entry point

The Solution

Same solution as this error “A project with an output Type of class library cannot be started directly”

Unable to copy file … chromedriver.exe

Error Message

Severity Code Description Project File Line Suppression State
Error Unable to copy file “C:\Users\User\Documents\Visual Studio 2015\Projects\UnitTestProject5\UnitTestProject5\chromedriver.exe” to “bin\Debug\chromedriver.exe

InnerException

The process cannot access the file ‘bin\Debug\chromedriver.exe’ because it is being used by another process

The Problem

The problem here is that your ChromeDriver is being used by another process. So when it’s trying to be copied, it can’t because it’s being used.

The Solution

Option A

  1. Open Task Manager and kill all chromedriver.exe processes

Option B

  1. Open Powershell command line.
  2. Execute command: Get-Process chromedriver | Stop-process
  3. This will kill all processes at once

 

An exception occurred while test discoverer ‘NUnit3TestDiscoverer’ was loading tests…

Error Message

An exception occurred while test discoverer ‘NUnit3TestDiscoverer’ was loading tests. Exception: Could not load file or assembly ‘nunit.engine’

The Problem

A caching issue with NUnit

The Solution

In this bug to NUnit, lorenh provides the solution about how to delete your cache.

A exception with a null response was thrown sending an HTTP request… ConnectFailure …

Error Message

A exception with a null response was thrown sending an HTTP request to the remote WebDriver server for URL http://localhost:19409/session/7114d633a2adbc5105f3f6c7abc7c596/url. The status of the exception was ConnectFailure, and the message was: Unable to connect to the remote server

InnerException

Unable to connect to the remote server

The Problem

Compatibility of Selenium WebDriver with a browser is the culprit here. This is the largest burden in my behind, and has been for years now…

This will probably continue until Selenium WebDriver is a W3C standard that is integrated into each browser. Until then, we will keep having these issues.

This error occurred to me with:

  • Chrome 55,56
  • ChromeDriver 2.27
  • Selenium WebDriver 3.0.1

The Solution

  1. Use ChromeDriver for all your test automation practice. Until I tell you it’s okay to use other Drivers.
  2. Make sure that your Chrome Browser and your ChromeDriver version are compatible.
    • You can see this information on the ChromeDriver download page

      How to tell if ChromeDriver is compatible with Chrome Browser

      How to tell if ChromeDriver is compatible with Chrome Browser

  3. Upgrade your Chrome and your ChromeDriver if you must
    • Warning: It’s almost impossible to downgrade ChromeDriver, so don’t try
  4. Download the latest Selenium WebDriver API Nuget package
  5. Rebuild your whole solution with all of these new resources
  6. Try to run your tests again
    • If this doesn’t work, restart your computer and try again.
I fixed my #Selenium ChromeDriver error, using this post https://wp.me/p7absY-4E

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A exception with a null response was thrown sending an HTTP request to the remote…

Error Message

Similar to the error above, but it’s slightly different in wording and message.

Selenium.WebDriverException: ‘A exception with a null response was thrown sending an HTTP request to the remote WebDriver server for URL http://localhost:25675/session. The status of the exception was ReceiveFailure, and the message was: The underlying connection was closed: An unexpected error occurred on a receive.’

InnerException

Unable to connect to the remote server

The Problem

You may have noticed that this page has one trend. Compatibility of Selenium WebDriver with a browser. This the largest burden in many of my behind, and has been for years now. This will probably continue until Selenium WebDriver is a W3C standard that is integrated into each browser. Until then, we will keep having these issues.

This error occurred to me with:

  • Chrome 56
  • ChromeDriver 2.27
  • Selenium WebDriver 3.0.1.0

The Solution

  • Update your Chrome browser to version 57.0
  • This did the trick for me. Keep in mind that maybe your versions of browser and ChromeDriver may be different. However, if you receive this error, just upgrade your browser until it fits into the support matrix of ChromeDriver release logs.

Cannot find Firefox binary in PATH …

Error Message

OpenQA.Selenium.WebDriverException: Cannot find Firefox binary in PATH or default install locations. Make sure Firefox is installed. OS appears to be: Vista

The Problem

The Selenium Webdriver team is making updates to Selenium to prepare it for Selenium 3.0. Also, the Mozilla team is making changes to the Firefox architecture to support the in built capabilities for Selenium Webdriver. Therefore, working with the latest versions of Selenium Webdriver and Firefox is going to cause you some issues. At least for the next few months. I believe that a stable 3.0 version will be released by Christmas.

The Solution

You can use the versions that I show in the Complete Selenium Webdriver Course:

  • Selenium Webdriver v 2.51.0 – just be sure to select this version in Nuget Package Manager when downloading
  • Firefox v 39.0

Get old Firefox versions

With the above installed, everything in this course for you should work without problems.

System.SecurityExceptions (multiple options)

Error Message

Almost any error message that contains SecurityException or something being “Inaccessible”

Here is a specific example that deals with NLog:

Error Error initializing target ‘EventLog Target[eventlog_wrapped]’. Exception: System.Security.SecurityException: The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security.
at System.Diagnostics.EventLog.FindSourceRegistration(String source, String machineName, Boolean readOnly, Boolean wantToCreate)
at System.Diagnostics.EventLog._InternalLogNameFromSourceName(String source, String machineName)
at System.Diagnostics.EventLog.LogNameFromSourceName(String source, String machineName)
at NLog.Targets.EventLogTarget.InitializeTarget()
at NLog.Targets.Target.Initialize(LoggingConfiguration configuration)
The Zone of the assembly that failed was:
MyComputer

The Problem

It’s stupid if you ask me, but a certainly recurring problem…

For whatever reason, Visual Studio sometimes requires you to start it as an Administrator. I believe this is after first installation or any kind of modification to Visual Studio.

The Solution

  1. Right click your Visual Studio icon
  2. Select “Run as administrator”
  3. Perform whatever operation you were previously trying to perform.
  4. The error should now be fixed

PS. You don’t need to keep running it as Administrator after this. At least it’s a one time action.

System.TypeInitializationException

System.TypeInitializationException: System.TypeInitializationException: The type initializer for ‘Framework.Browser’ threw an exception. —> OpenQA.Selenium.WebDriverException: Failed to start up socket within 45000 ms. Attempted to connect to the following addresses: 127.0.0.1:7055.

Or something like this?

 

OpenQA.Selenium.WebDriverException : Unexpected error. System.Net.WebException: Unable to connect to the remote server —> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it

Today is your lucky day because I am going to help you resolve these really annoying errors!

The Problem

The problem is a standard compatibility issue between Selenium WebDriver and your version of a browser. As I am writing about this, the latest WebDriver version is 2.53.1. The latest Chrome version is 51.0 and the latest Firefox version is 46.0. Therefore, the Selenium WebDriver API does not get updated as often as Chrome or Firefox.

When different types of browsers such as Chrome or Firefox get updated, there is a chance that this update will break the Selenium API.

In our industry, this is known as a regression. Therefore, when you get the latest version of your browser, you may be using a Selenium WebDriver version that does not support the latest features of that browser. At this point, you will receive an ugly error that looks like this:

System.TypeInitializationException

Now, you will spend the next day wondering how your Selenium code used to work yesterday and today it just stopped working.

The Solution

Downgrade your appropriate browser to the version supported by the latest Selenium Driver. This might be Firefox, ChromeDriver, IEDriver and so on.

In this example I teach you how to downgrade Firefox.

An exception occurred while invoking executor ‘executor://mstestadapter/v2’ …

Error Message

This message is in your Output pane in “Output from Tests”.

An exception occurred while invoking executor ‘executor://mstestadapter/v2’: Constructor on type ‘Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter.Execution.UnitTestRunner’ not found.

The Symptoms

You are trying to run your Automation tests using MSTest, but they don’t run. They start going, but then Visual Studio just stops. When you check the Output pane, you see the message described above.

MSTest has a bug and needs an update. I had version 1.1.11 installed and it caused me this issue.

The Solution

  1. Using NuGet Package manager, update your MSTest.TestAdapter and MSTest.TestFramework NuGet packages to the latest version. I updated to 1.1.18.
  2. Restart Visual Studio
  3. Re-run your automation tests

System.InvalidOperationException : unknown error: Chrome version must be…

Error Message

System.InvalidOperationException : unknown error: Chrome version must be >= 54.0.2840.0

The Problem

Another issue with compatibility of ChromeDriver with Chrome Browser. In this case it was Chrome version 48.0 not working with ChromeDriver version 2.27

The Solution

Upgrade your Chrome browser to the version supported by ChromeDriver. For example, ChromeDriver 2.27 supports Chrome 54 – 56 according to their release notes.

Issues with Firefox and Selenium 3.0 Compatibility

Error Message

Nothing specific, if you see weirdness with Firefox and Selenium 3.0, this solution will probably work for you

The Problem

The #1 problem that people complain about is that their Firefox Driver doesn’t work with Selenium 3.0. I get this question about 72 times per day. Let me help.

The Selenium Webdriver team released Selenium 3.0. However, the Mozilla team is making changes to the Firefox architecture to support the in built capabilities for Selenium Webdriver. Therefore, working with the latest versions of Selenium Webdriver and Firefox is going to cause you some issues until the Firefox team finishes implementing Gecko Driver. By the way, you won’t be using Firefox driver any more.

The Solution

If you are starting to use Selenium Webdriver, your easiest route is to start by using Chrome Driver. You can use the latest version of Selenium and the latest version of Chrome Driver.

Don’t touch Gecko Driver (replacement of FirefoxDriver) until it is more mature. Otherwise, you’re bound to cause yourself problems.

Element is not clickable at point (X, Y). Other element would receive the click…

Error Message

System.InvalidOperationException : unknown error: Element is not clickable at point (111, 700). Other element would receive the click: <div class=”et_social_heading”>…</div>  (Session info: chrome=45.0.2454.93)  (Driver info: chromedriver=2.15.322448 (52179c1b310fec1797c81ea9a20326839860b7d3),platform=Windows NT 6.1 SP1 x86_64)

The Problem

The problem here is that the element that you are trying to click is either covered by another element, or simply not visible. Here is an example. If you go to www.ultimateqa.com and try to click the Start Here button when you are a bit scrolled down, the header covers up the button. As a result, even though the button is on the page, it is not clickable because the header is covering it up.

Element not clickable example

Element not clickable example

The Solution

To fix this problem, you need to make the element visible. Specifically, the center of the element needs to be clickable as that is where Selenium tries to click. Whether that means scrolling up, or hovering over an element to close it, or clicking on an element that is expanded to minimize it. There are multiple solutions. But simply, make sure that your element is visible for clicking. If there is no element on top of the one you want to interact with, you should be fine.

You can scroll the element into view like this:

Or you can use the actions class to move to element before interacting with it like this:

Unit tests not showing up in Visual Studio test explorer

Error Message

Something like this below:

…\MSTest.TestAdapter.1.2.0/build/_common/Microsoft.VisualStudio.TestPlatform.MSTest.TestAdapter.dll

The Problem

  • Visual Studio Version: 15.0.X
  • MSTest Adapter version: 1.18

There seems to a be bug with Visual Studio and the Visual Studio test adapter when you are trying to work with the versions listed above.

The Solution

To fix this problem, you need to update Visual Studio to version 15.5.2 and your MSTest Adapter in the Nuget package manager to version 1.2.0.

Are your Selenium tests not showing up in the Visual Studio Test Explorer? Here is the fix from…

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Nikolay Advolodkin
Nikolay Advolodkin is a self-driven SDET on a lifelong mission to create profound change in the IT world and ultimately leave a legacy for his loved ones, community, and the world at large. Today, he serves as the CEO and Test Automation Instructor at UltimateQA.com and contributes informative articles to leading test automaton websites like SimpleProgrammer.com and TechBeacon.com

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  • Keyrad Abasi

    I got this exception while executing a simple program to test selenium:

    Unhandled Exception: System.TypeLoadException: Could not load type ‘OpenQA.Selenium.Chrome.ChromeDriver’ from assembly ‘WebDriver

    What is the problem?

    • Nikolay Advolodkin

      Are you using Java bindings? If so, I am not familiar with Java binding errors.

      • OpenQA.Selenium.WebDriverException : A exception with a null response was thrown sending an HTTP request to the remote WebDriver server for URL http://hub-cloud.browserstack.com/wd/hub/session/6a9462564325d212d46b32980d2f14252f1e8313/keys. The status of the exception was KeepAliveFailure, and the message was: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.
        —-> System.Net.WebException : The
        Problem occurs when tests run using TFS release nightly build

  • Kaushal Shah

    I am trying to create POM Framework. Code was working till yesterday and from today same code is giving “ArgumentException was unhandled by user code”
    An exception of type ‘System.ArgumentException’ occurred in WebDriver.Support.dll but was not handled in user code

    Additional information: The SearchContext of the locator object cannot be null

    I have sanity script – which is calling test script and that script is refering to page object class. Error is coming in the pageobject class @ PageFactory.InitElemtns(driver, this); line below:
    public LandingPage(IWebDriver driver)
    {
    this.driver = driver;
    PageFactory.InitElements(driver, this);
    }

    • Nikolay Advolodkin

      DOn’t use PageFactory it has tons of issues. That’s probably why you are getting that error. Use properties to just return your elements.
      If you want to know how to structure you page objects well, take a look at this Page Objects Course

      • Anonymous

        wise advice

  • Dave

    Hi Nikolay, I am loving the course!

    I have encountered some strange issues in Visual Studio. I am using Windows 10 Home, Visual Studio Professional 2017, ChromeDriver 2.33, supports Chrome version 62+, using Chrome Version 62.0.3202.75 and Selenium.Support and Selenium.Webdriver version 3.7.

    1. In “How to download and install Selenium Webdriver” I have noticed as you type “var driver = new ChromeDriver();” the “using OpenQA.Selenium.Chrome;” gets added automatically, not in my case. I had to type in myself.

    2. Intellisense is not working.

    3. Chromedriver > Properties (“How to download Chrome Driver) is missing “Advance” category hence “Copy to output directory” is unavailable.

    What am I missing?

    Thanks in advance.

    • Nikolay Advolodkin

      Excellent 🙂

      • Dave

        Hi Nikolay, can you please answer 3rd. question, i.e. In Visual Studio > Solution Explorer, Chromedriver > Properties (“How to download Chrome Driver” video) is missing “Advance” category hence “Copy to output directory” is unavailable.

        What can I do to fix this?

        Thanks.

  • Dave

    Just wanted to mention that I found the solution to Visual Studio 2017 Intellisense fix. Apparently there is a bug!

  • Sharmila

    Hello,

    I am having trouble identifying an element. My application has a left navigation menu called New and when expanded it shows sub menus.

    I was able to identify New and then clicked on it. But failing to identify the sub menu.

    This is a part of the code that I have so far …
    IWebElement navmenu = driver.FindElement(By.XPath(“//*[@id=’subMenuModules’][8]”));
    navmenu.Click(); //success
    Thread.Sleep(TimeSpan.FromSeconds(15));

    IWebElement contactclick = driver.FindElement(By.XPath(“//*[@id=’collapse’]/paper-menu/div/paper-item[1]”));
    contactclick.Click(); //failing .
    https://uploads.disquscdn.com/images/dd5530de7ce43e4a7301f4f35bdaff017ab30c90da6ff9a4c9c779bff83c96e1.png
    Please see attached screenshot for the HTML.

    Thank you and appreciate your support.
    -Sharmila

  • Baurzhan Dosym

    Hi, I have problems with IE 11 – (IE11 in test requirements)

    What I did:
    I have downloaded IE driver from http://selenium-release.storage.googleapis.com/index.html?path=3.9/
    name of the file IEDriverServer_Win32_3.9.0.zip -> unzipped -> Placed to WebBrowserFactory =
    I can run IE11 browser and open target website

    What is wrong:
    If I run 6 tests together
    I can’t open any locator – So FIRST test is ok – but for rest five tests I have error bellow:
    ————–
    “OpenQA.Selenium.NoSuchElementException: Unable to find element with css selector == #loginUsername”
    ————-
    but same code works perfect in Google Chrome
    Latest version try WebDriver/IEDriver v3.9, v3.9.1, v3.8 – different version combinations

    • What do you mean run tests “together”. Do you mean in parallel, all at the same time? Or do you mean as a suite of 6 tests, one at a time?

      If it’s the former. The problem isn’t I É. The problem is that your tests are probably not independent, making parallel execution impossible.

      • Baurzhan Dosym

        My bad. Not good explanation. So I have 6 tests now. not in parallel – And I click Run All at Test explorer

        • Okay, so then it might be a problem with IE then. Remember that different browsers render HTML differently. In fact, I feel like IE doesn’t support CSS locators if I remember correctly?
          May I as why you are using IE? Almost nobody in the world uses that browser. In fact, Microsoft no longer suports it – https://venturebeat.com/2016/01/12/microsoft-ends-support-for-ie8-ie9-ie10-and-windows-8/
          That’s why they created Edge.
          So although I might be able to help you fix the running tests on IE. I think that we’re placing a band aid on a larger problem that will come back and kill your automation. The problem being that you use IE. At worst, use Edge. At least it’s build with Selenium integration.
          Sorry if that’s not the answer you’re looking for, I need to be honest and help people to come up with the best solution possible.

          • Baurzhan Dosym

            May be…. I use these
            private IWebElement UserField => Driver.FindElement(By.Id(“loginUsername”));
            private IWebElement PasswordField => Driver.FindElement(By.Id(“loginPassword”));
            private IWebElement LoginButton => Driver.FindElement(By.Id(“loginSignInButton”));

          • That’s not what your error shows:
            “OpenQA.Selenium.NoSuchElementException: Unable to find element with css selector == #loginUsername”

            Also, the question is, do these tests work in Chrome fine? But then don’t work in IE? If the answer is yes, it’s your locators. You need a different strategy for IE.

  • Jim

    I am going through the examples in the LightPomFrameworkTutorial package. I am getting a build error on many of the examples. The error is “AutomationResources.dll could not be found”

    As a specific example, I am working with SampleApp2. When I build the solution I am getting the following error:

    Severity Code Description Project File Line Suppression State
    Error CS0006 Metadata file ‘D:VS ProjectsLightPomFrameworkTutorialAutomationResourcesbinDebugAutomationResources.dll’ could not be found SampleApp2 D:VS ProjectsLightPomFrameworkTutorialSampleApp2CSC 1 Active

    I looked in the ‘AutomationResourcesbinDebug’ folder and as the error states, there is no AutomationResources.dll there.

    This same error is coming up during building of many of the examples.

    How can I correct this error?

    Thanks,
    Jim

    • do you have chromedriver.exe being ran in the background? If so, kill it and try again

      • Jim

        Wow, that worked. You’re amazing!!!

  • Jim

    A number of the examples in “ElementIdentification.cs” (that show the various ways to use an Element Locater) are failing.
    The following is one example of the errors I am getting:

    ProjectsLightPomFrameworkTutorialElementInteractionsElementIdentification.cs:line 44
    Result Message:
    Test method ElementInteractions.ElementIdentification.ElementIdentificationTest threw exception:
    OpenQA.Selenium.NoSuchElementException: no such element: Unable to locate element: {“method”:”name”,”selector”:”NameExample”}
    (Session info: chrome=65.0.3325.181)

  • Jim

    No problem. I’ll move on to ‘Implicit and explicit waits’ in the mean time. Thanks for all your efforts!

  • Andy

    Hi Nikolay, great course, really enjoying it so far!

    I’m just having a few issues with nlog and getting data written to a file in the following location: c:temp${appName}Debug.log”

    I’ve tried copying the code from the config file on your github repository but have had no joy. However, when I debug the tests and hit the line of code relating to the logging of data I get an error as below. The test then runs successfully but I don’t see a log file being generated(screenshot 1)
    https://uploads.disquscdn.com/images/b3f65c9ef623284e06d5b8c6197c6092e9b62248a892203ea421d1f1ab479e6b.png

    For reference the HomePage code is below too(screenshot2)

    • I can recommend that you try 2 things:
      1. Compare your Nlog.config to mine. And also your source code to mine. What’s the difference?
      2. Try to start Visual Studio as administrator and let me know if that helps.

  • Andy
  • Jim

    Hi Nikolay,

    I found an issue in one of the videos I thought you’d want to be aware of.

    Answer to why the test is flaky:
    The audio cuts out around 0:41

    Besides that, this is the most amazing Selenium (and C#) training I have ever seen!

    Thank you for putting this course together.

    Jim

    • Hey Jim, thank you so much. I’ll have that fixed this weekend! Appreciate you taking time out of your day to report this issue 🙂

      Thanks for the compliment as well. I’m actually updating a bunch of stuff, so it’s about to be even better 🙂

  • Jim

    Hi Nikolay,

    Just fyi, the section:
    Different types of Visual Studio projects > Class library project

    doesn’t have audio until 3:34

  • Jim

    In the code for the lesson on Element Identification, the following code needs to be changed for this test to pass:

    From inside ElementIdentification.cs …

    From:

    [TestMethod]
    [TestCategory(“Element Interrogation”)]

    public void ElementInterrogation()
    {
    driver.Navigate().GoToUrl(“https://www.ultimateqa.com/automation/”);
    var myElement = driver.FindElement(By.XPath(“//*[@href=’http://courses.ultimateqa.com/users/sign_in’]”));
    }

    To:

    [TestMethod]
    [TestCategory(“Element Interrogation”)]

    public void ElementInterrogation()
    {
    driver.Navigate().GoToUrl(“https://www.ultimateqa.com/automation/”);
    var myElement = driver.FindElement(By.XPath(“//*[@href=’https://courses.ultimateqa.com/users/sign_in’]”));
    }

    So, the change is from @href=’http: to @href=’https:

    I hope this helps,
    Jim

    • Thanks Jim 🙂
      All fixed. Yea, we updated to HTTPS and didn’t update the code.

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