Visual Studio - suddenly cannot debug tests

Question

I'm not sure what I did, but all of a sudden, my Visual Studio 2012 will not debug any tests.

If I select a test from the Test Explorer and tell it to run, it simply outputs this in the Test Output window:

> ------ Discover test started ------
> ========== Discover test finished: 29 found (0:00:01.3371755) ==========
> ------ Run test started ------ Process with an Id of -1 is not running.
> ========== Run test finished: 0 run (0:00:01.4711861) ==========

what the heck does that mean?! After doing this a few times, the error changed to:

The Operation was Cancelled

which I sure didn't do.

It's doing this on every test in the list.

however, I can RUN the tests no problem, and they pass... but I cannot debug the tests.

What might I have done? I did not actively go into any settings and change anything, perhaps a stray click somewhere, but where?

running as admin didn't work, rebooting didn't work... but somehow rebooting and running as admin did work... I changed nothing else! sigh... well it's working if it keeps up will post this as answer :/ — SelAromDotNet, Aug 02 '13 at 19:20
Possible duplicate of [Visual Studio "Debug Unit Test" fails to hit breakpoints](https://stackoverflow.com/questions/4332112/visual-studio-debug-unit-test-fails-to-hit-breakpoints) — pushkin, Feb 01 '19 at 19:38
Related post - [Visual Studio 15.8.1 not running MS unit tests](https://stackoverflow.com/q/51967866/465053) — RBT, Apr 27 '21 at 07:31

score 64 · Answer 1 · answered Oct 24 '17 at 05:44

64

I encountered this today. I tried closing the solution but it didn't work. My mistake I set my solution to Release Mode instead of Debug Mode. I set it to Debug then it worked as expected.

I'm using VS 2015 professional.

answered Oct 24 '17 at 05:44

Tom Mabaquiao

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If I could, I would hug your right now. This has been annoying me for hours lol. – Jason Evans Oct 15 '18 at 12:48
I fill so dumb, suddenly... – SeyoS Dec 04 '21 at 13:40

score 27 · Answer 2 · edited May 23 '17 at 10:30

I was getting the same output after upgrading a test project from VS 2010 to VS 2012 Ultimate Update 3. The message was displayed in Test Output window after using MSTest command to Debug Selected Tests.

I tried to debug tests using Resharper 8 Unit Test Session window. The message in the result window was "Test wasn't run".

The solution that helped me was to modify the test project settings to enable native code debugging as instructed at this link: Uncaught exception thrown by method called through reflection

In case the link does not work:

Go to the project right click and select properties.
Select 'Debug' tab on the left.
Go to ‘Enable Debuggers’ on the bottom
Check ‘Enable Native code debugging’ (or 'Enable unmanaged code debugging', depends on version) check box

Thanks to GalDude33 for posting the solution.

Alternatively make sure you don't have VS set to Release mode. I just made this mistake. You have to be on Debug in order to debug tests. — dyslexicanaboko, Apr 04 '17 at 04:46

score 24 · Answer 3 · answered Sep 24 '20 at 22:22

24

In my case, it was the launchSettings.json file which was causing the debugger not to be able to hit a breakpoint. Not sure why the file was present in a unit test type of project (probably some unwanted leftover), however, xunit seemed not to ignore it. I simply deleted the file and I was able to debug the unit tests again.

Env: Microsoft Visual Studio Enterprise 2019 Preview (Version 16.8.0 Preview 3.1)

answered Sep 24 '20 at 22:22

rocky

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Thank - You - KING! – JohannSig Oct 21 '21 at 23:11
B I N G O ! ! ! ! – juagicre Jun 16 '22 at 12:47

score 17 · Answer 4 · answered Jul 09 '14 at 22:49

17

Have regularly the same issue with Visual Studio 2012.

Solution : close the current solution and reopen it.

In my case closing and reopening VS was not necessary.

answered Jul 09 '14 at 22:49

Pragmateek

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even " IT crowd" folks can fix this! It worked for me – Blue Clouds Dec 12 '16 at 12:20
2

Working for me in VS 2017. What precipitates the issue for me is stopping debugging; I have to let the debug session run to completion or it breaks the Debug Tests command. – System.Cats.Lol Aug 24 '18 at 17:25

score 14 · Answer 5 · answered May 26 '18 at 23:18

Async Tests - Symptoms in my scenario were similar in that my test was not executing and my breakpoint was not getting hit. The Test Explorer in Visual Studio could see the test, but I could not debug it. Running it acted as though it could not be found even though it could be seen in the Test Explorer.

In case it helps someone else, my issue was as simple as having to change the test method's signature from "async void" to "async Task".

Do this:

[TestMethod]
public async Task CorrectlyFailingTest()
{
  await SystemUnderTest.FailAsync();
}

Not this:

[TestMethod]
public async void CorrectlyFailingTest()
{
  await SystemUnderTest.FailAsync();
}

This was my case on VS2019 and it worked perfectly. – Rabel Obispo Jun 06 '19 at 14:27 — Rabel Obispo, Jun 06 '19 at 14:27

score 7 · Answer 6 · answered Nov 01 '18 at 20:15

7

I was unable to attach to my debugger because it was looking for test settings file.
If this is your issue then go to Test->Test Settings->Uncheck Local.testsettings option

answered Nov 01 '18 at 20:15

Matthew Peterson

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What's the reasoning behind the down vote? If you're referencing test settings that don't exist then it will cause issues with debugging unit tests. More info here: https://msdn.microsoft.com/en-us/library/ee256991.aspx?f=255&MSPPError=-2147217396 – Matthew Peterson Nov 02 '18 at 14:28
There seem to be loads of problems and associated solutions for this symptom, but this one was the one to help me. Disabling runsettings file in VS2017 works. Thanks! – Eike Mar 02 '20 at 09:59

score 6 · Answer 7 · edited Aug 30 '17 at 10:57

6

Please follow below steps. It worked for me

Steps.

1.Close your visual studio instances

2.Clean you temp files and prefetch files.

3.delete the files in project bin folder.

4.Restart the applications.

edited Aug 30 '17 at 10:57

Om Sao

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answered Aug 30 '17 at 10:11

swathi cv

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close all of my visual studio and clear temp and remove bin and obj folder works for me,thanks – Ali Yousefi Nov 20 '17 at 17:05
I wasn't sure about step2 so I skipped it and proceeded with Step3 then 4 and problem resolved. thank you @Om Sao ... – Tien Jan 25 '21 at 22:42
and @swathi cv !! – Tien Jan 25 '21 at 22:42

Youngjae · Answer 8 · 2020-08-14T06:40:58.297

5

For me, updating MSTest.TestAdapter and MSTest.TestFramework Nuget packages to latest version resolved the problem.

edited Aug 14 '20 at 06:40

answered Aug 24 '17 at 08:45

Youngjae

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THANK YOU! This worked for me after fussing over this for hours. – susieloo_ Dec 08 '21 at 00:42

score 4 · Answer 9 · answered May 29 '18 at 10:39

4

Ensure your test project is part of the projects to build.

Right click your solution from Solution Explorer
Go to Set StartUp Projects..
Click on Configuration Properties and ensure your test project is checked for build

answered May 29 '18 at 10:39

Peter Ombwa

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1
3

If you are using a deployment tool - and not doing Tests for CI/CD - you may have to uncheck the Unit Test project - for your CI/CD and when you add new tests - you have to recheck it for your Unit testing again - which would be nice to have a warning on adding a new test - but you have to manually check if it is checked on your Debug build. – Mark W. Mitchell Nov 01 '18 at 15:34

score 3 · Answer 10 · edited Apr 28 '22 at 20:49

3

In my case, my symbols weren't loaded.

I had to go to Tools -> Options -> Debugging -> Symbols and select "Load all modules, unless excluded" for breakpoints to get hit.

edited Apr 28 '22 at 20:49

Hanlet Escaño

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answered Feb 01 '19 at 19:52

pushkin

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score 2 · Answer 11 · answered Apr 21 '16 at 07:35

I was having similar issue in VS2015. Only one unit test could not be debugged in my case. Debugger would initialize a test, but would not debug test itself, nicely exiting. The problem was in Resharper importing Newtonsoft.Json library without enabling NuGet package for the project. (I used Alt+Enter to automatically import the library)

Solution was to install Newtonsoft.Json NuGet package for test project.

score 2 · Answer 12 · answered Oct 17 '18 at 19:31

2

As of Visual Studio 2017 (15.8), this can happen when the Live Unit Testing feature is active. There's no clear message in the output; it just starts and stops without debugging. The solution is stopping the live testing so then you can debug the test normally.

answered Oct 17 '18 at 19:31

Arturo Torres Sánchez

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I even have to rebuild the project after deactivating live testing. After that each test is showing a blue exclamation mark, and debugging is working once again. – Kai Hartmann Sep 10 '19 at 13:51

score 1 · Answer 13 · answered Aug 14 '13 at 12:53

1

Take a look at the following link there is an update that fixing it. Visual studio 2012 update 3.

http://social.msdn.microsoft.com/Forums/vstudio/en-US/e96f53c7-dc8c-4274-8756-eb745de701e8/visual-studio-2012-update-3-cant-debug-unit-test

answered Aug 14 '13 at 12:53

user2682517

11
1

What's confusing is that in the link they call it "VS2013 Update 3". – sgryzko Oct 04 '13 at 23:25

score 1 · Answer 14 · answered Aug 18 '16 at 14:43

1

When I use Visual Studio 2012, for some reasons, if I use shortcut ctrl R+T, it will hit the break point. But if I click "Run All" or "Run Selected Test" on Test Explorer, it won't. Visual Studio 2013 works fine both ways though.

answered Aug 18 '16 at 14:43

paibamboo

2,804
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16

Did you actually use Ctrl+R, Ctrl+T (which is Debug, not Run)? for Run it’s expected not stop on breakpoint. – Michael Freidgeim Jun 02 '21 at 12:48

score 1 · Answer 15 · answered Jan 12 '18 at 01:50

1

Hitting "Run tests" will not trigger the brakepoints.

To debug your code and stop at a breakpoint in a test:

Right-click > Debug Tests

or

"Test" tab > Debug > All tests

answered Jan 12 '18 at 01:50

Chris Mathew

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score 1 · Answer 16 · answered Nov 08 '18 at 11:40

This might not be a solution to your problem specifically, but I also couldn't debug a test that I had written. Turns out the solution was quite simple:

Change the method from private to public. I don't know why debugging isn't possible within private methods, but it's probably got something to to with the [Test] attribute's implementation. Hope this helps anyone struggling with a similar problem in the future!

Ibrahim Amer · Answer 17 · 2019-03-05T13:30:45.443

1

None of the proposed solutions worked for me. What worked for me is changing the unit test project and all dependent projects' platform target to Any CPU instead of x64 which is some kind of a workaround not a real fix !!

EDIT

The target platform for a unit test project could be changed from test settings not from the project's properties. Refer to this answer for more.

edited Mar 05 '19 at 13:30

answered Mar 05 '19 at 13:13

Ibrahim Amer

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thanks a lot! I change all my projects to Any CPU and worked! – Hernaldo Gonzalez Oct 22 '19 at 19:58
1

@HernaldoGonzalez glad to hear that!. Happy hacking my friend :)) – Ibrahim Amer Oct 23 '19 at 21:40

score 1 · Answer 18 · answered Jun 24 '20 at 15:19

Just like you guys, I wasn't able to Debug nor Run Unit Tests of my MSBuild Tests Project in Visual Studio 2019 16.6.2. The code I wanted to Unit Test is in a Class Library based on .Net 4.6.2. The Test Explorer always stated "Tests Not Run" with the blue information icon beneath.

So I just tried to create a new Unit Test from within the Code File of the Method I wanted to test => and it worked! Exact steps I went through: In the C# File go to the method, right click on it and select "Create Unit Tests" and let the dialog create a new project. After adding the Test Code from my original files all went fine and I am able to Debug and Run my Test Methods!

Hope this simple solutions helps some of you, too. Best regards

score 1 · Answer 19 · answered Dec 29 '20 at 00:21

1

For me I went to Test explore -> setting -> processor Architecture For AnyCPUProjects and changed it to X64 and it worked for me.

answered Dec 29 '20 at 00:21

Gaurav Joshi

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score 1 · Answer 20 · edited Jul 13 '21 at 21:08

1

With me I simply added xunit.runner.visualstudio (latest stable version at the time was 2.4.2) and that did the trick.

edited Jul 13 '21 at 21:08

Dharman

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answered Jul 13 '21 at 21:02

Harold_Finch

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score 1 · Answer 21 · answered Nov 07 '21 at 09:55

1

I had the same problem in Visual Studio 2019.

For me worked using Repair command of Visual Studio Installer.

answered Nov 07 '21 at 09:55

gsscoder

3,088
4
33
49

score 0 · Answer 22 · answered May 17 '16 at 17:12

0

For me the problem was that my config file (app.config) didn't have the Debug Transformation file (app.Debug.config), once I added it start working/debugging again.

answered May 17 '16 at 17:12

Jaider

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score 0 · Answer 23 · answered Feb 28 '18 at 21:34

For me the problem was that after upgrading to 2017 v15.5.7 my solution's properties got changed somehow. Which made it where I could run the test once in debug mode, but not again, unless I restarted VS, then it would work again, once. Once I set it back it worked again. The setting was, and should be, for me, Solution > Common Properties > Startup Project > Multiple startup projects. Somehow it got set to "Single startup project".

Marco Staffoli · Answer 24 · 2018-06-28T13:27:40.540

0

Check that the test project and the main project are using the same framework version.

edited Jun 28 '18 at 13:27

answered Jun 28 '18 at 13:14

Marco Staffoli

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score 0 · Answer 25 · answered Jul 29 '18 at 14:49

0

Solution: Select 'Debug Unit Tests' or 'Run Unit Tests' instead of 'Debug Tests' or 'Run Tests'.

answered Jul 29 '18 at 14:49

Ravi Kant Shivhare

11
1

mhapps · Answer 26 · 2018-10-08T14:26:02.130

app.config problem references can unwittingly cause the debugger not to attach and breakpoints not to be hit when debugging test projects. This file may have been updated by packages or has gone out of date.

Solution: I generally copy then remove all dependencies under the runtime tag from the test project's app.config. Debugging usuually starts working after this but some references may need to be added back if assemblies can't be found.

Yiping · Answer 27 · 2018-10-21T07:19:16.657

0

In my case, the break point can't be hit if there is build warning(s). I can verify this by toggle the line of code with warning. It was a unused string with length 66000. (Warning CS0219 The variable 'XXXXXXX' is assigned but its value is never used)

I guess the compiler removed this line so the symbol mapping failed?

edited Oct 21 '18 at 07:19

answered Oct 21 '18 at 07:10

Yiping

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10
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score 0 · Answer 28 · answered Nov 12 '18 at 09:24

For me the following worked:

Close Solution
Close Visual Studio
Delete the contents of "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\"
Delete the contents of "C:\Windows\Microsoft.NET\Framework64\v2.0.50727\Temporary ASP.NET Files\"
Open Visual Studio
Open Solution

score 0 · Answer 29 · answered Mar 09 '20 at 14:12

0

I just faced a similar issue, where NUnits TimeoutAttribute caused the test to be cancelled when debugging without a meaningful message.

Removing the attribute from the test fixed the issue.

answered Mar 09 '20 at 14:12

nozzleman

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score 0 · Answer 30 · answered May 14 '20 at 12:20

0

If you created a project in an older Visual Studio and are now using VS 2019, you must install the Microsoft.VisualStudio.TestPlatform library and update others.

answered May 14 '20 at 12:20

H2Oc

1

score 0 · Answer 31 · answered Dec 10 '20 at 17:25

0

In my case, it was because I was using a non-static method as the dynamic data source for a Data test method.

answered Dec 10 '20 at 17:25

Eric

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score 0 · Answer 32 · answered Dec 14 '21 at 01:06

0

In my case it was the test project having a reference Microsoft.NET.Sdk.Function:

    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.0.1" />

Once it was removed the debugger stops at the breakpoints set.

answered Dec 14 '21 at 01:06

tymtam

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score -1 · Answer 33 · answered Mar 31 '14 at 12:26

Saw this post while investigating the same issue; This solved it for me (posting this in case others encounter the same):

System: Windows 7, 64 bit on Intel i5

Actions:

Downloaded VS2012 Update pack 4 from Microsoft
Set the UAC (press Windows key, enter UAC) to Default
Uninstall Update pack 4
(Mandatory) restart
Set the UAC to Default again (somehow it got reset to none)
Install Update pack 4

The UAC thing was something that was mentioned somewhere else, but I don't know if this was a necessary step.

Visual Studio - suddenly cannot debug tests

33 Answers33

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