Last Updated: 18 Mar 2021 13:28 by ADMIN
When the ports with which the DebugWindow should operate are changed in the DebugWindow host configuration the process is started with the default values instead of the new values.
Last Updated: 05 Mar 2021 14:20 by ADMIN

Attempt to use JustMock VSTest v.2 task to run the elevated mode tests with coverage when the "Test platform version" option is set to value "Installed by Tools Installer" fails with error:

Telerik.JustMock.Core.ElevatedMockingException: Cannot mock '<target type goes here>'. The profiler must be enabled to mock, arrange or execute the specified target.
Detected active third-party profilers:
* {9317ae81-bcd8-47b7-aaa1-a28062e41c71} (from process environment)
Disable the profilers or link them from the JustMock configuration utility. Restart the test runner and, if necessary, Visual Studio after linking.

Last Updated: 05 Mar 2021 14:19 by ADMIN
The exception description does not clearly state that there is an issue with the member which is a target of the mocking which could easily lead to confusion. Attached sample project reproducing the issue.
Last Updated: 10 Feb 2021 11:41 by ADMIN
Implement support for code coverage in the JustMock VSTest v.2 Azure Pipeline task similar to the code coverage option available in VS Test task.
Last Updated: 10 Feb 2021 11:10 by ADMIN

Having the following COM interop class

public class MyComObjectClass : IMyComObject, MyComObject
    public MyComObjectClass();

    public virtual string Echo(string message);

and the sample class that uses it:

public class MyComObjectClassProxy
    public string Echo(string message)
        IMyComObject itf = null;
            itf = new MyComObjectClass();
            return itf.Echo(message);
            if (itf != null)

When I try to call the arranged constructor I am getting an error "Cannot create instances of type requiring managed activation", the unit test code:

public void TestMethod1()
    var mock = Mock.Create<MyComObjectClass>();
    Mock.Arrange(() => new MyComObjectClass()).Returns(mock);

    var sut = new MyComObjectClassProxy();
    var actual = sut.Echo("Message");

    Assert.AreEqual(string.Empty, actual);
Last Updated: 10 Feb 2021 10:47 by ADMIN
Created by: Toshio
Comments: 1
Type: Feature Request
An attempt to use future mocking fails. The attached sample demonstrates the issue.
Last Updated: 02 Feb 2021 09:35 by ADMIN

I have a class, which has a private async method, which has a local function, like the following example


internal class TestClass



        private async Task<bool> TestPrivateMethod()
            var x = await TestLocalFunction();
            return x;

            async Task<bool> TestLocalFunction()
                await Task.Delay(5);
                return true;


When I try to mock the local function, thows an error "System.MissingMemberException : C# 7 local function 'TestLocalFunction' with the given signature was not found inside method 'TestPrivateMethod'"


var testClassInstance = Mock.Create<TestClass>(Behavior.CallOriginal);

Mock.Local.Function.Arrange<Task<bool>>(testClassInstance, "TestPrivateMethod", "TestLocalFunction").Returns(Task.FromResult(true));


Last Updated: 02 Feb 2021 09:32 by ADMIN
Created by: Calvin
Comments: 7
Type: Bug Report

Thread leak in JustMock

I am a member of the Visual Studio Perf Reliability team


Recently, I’ve found several customer dumps with huge # of threads.

In this dump:

Watson : Cab Search (





Progress® Telerik® JustMock Feedback Portal


There are 2084 threads using 2G mem, most with the stack below:

This is caused by threadpool starvation: the JustMock call ties up a thread for more than 1 second, then another request comes in.

The CLR will create an additional thread after 1 second to satisfy the request. This keeps happening and creates thousands of threads, each with size 1Meg.


00 ntdll!NtWaitForMultipleObjects
01 KERNELBASE!WaitForMultipleObjectsEx
02 clr!WaitForMultipleObjectsEx_SO_TOLERANT
03 clr!Thread::DoAppropriateAptStateWait
04 clr!Thread::DoAppropriateWaitWorker
05 clr!Thread::DoAppropriateWait
06 clr!SOIntolerantTransitionHandler::SetNoException
07 clr!CLREventBase::WaitEx
08 clr!CLREventBase::Wait
09 clr!AwareLock::EnterEpilogHelper
0a clr!ThreadDebugBlockingInfo::PopBlockingItem
0b clr!DebugBlockingItemHolder::{dtor}
0c clr!AwareLock::EnterEpilog
0d clr!AwareLock::Enter
0e clr!AwareLock::Contention
0f clr!JITutil_MonReliableContention
10 Telerik_JustMock_DebugWindow_Service_Client!Telerik.JustMock.DebugWindow.Service.Client.ConnectionSetupServiceClientBase<Telerik.JustMock.DebugWindow.Service.Proxy.TraceEventsSubscriptionServiceProxy>.get_ServiceAvailable
11 Telerik_JustMock_DebugWindow_Service_Client!Telerik.JustMock.DebugWindow.Service.Client.SessionServiceClientBase<Telerik.JustMock.DebugWindow.Service.Proxy.MockRepositorySubscriptionServiceProxy>.KeepAliveTimer_Elapsed
12 System_ni!System.Timers.Timer.MyTimerCallback
13 mscorlib_ni!System.Threading.TimerQueueTimer.CallCallbackInContext
14 mscorlib_ni!System.Threading.ExecutionContext.RunInternal
15 mscorlib_ni!System.Threading.ExecutionContext.Run
16 mscorlib_ni!System.Threading.TimerQueueTimer.CallCallback
17 mscorlib_ni!System.Threading.TimerQueueTimer.Fire
18 mscorlib_ni!System.Threading.TimerQueue.FireNextTimers
19 mscorlib_ni!System.Threading.TimerQueue.AppDomainTimerCallback
1a clr!CallDescrWorkerInternal
1b clr!CallDescrWorkerWithHandler
1c clr!MethodDescCallSite::CallTargetWorker
1d clr!MethodDescCallSite::Call
1e clr!AppDomainTimerCallback_Worker
1f clr!ManagedThreadBase_DispatchInner
20 clr!ManagedThreadBase_DispatchMiddle::__l16::Cleanup::{dtor}
21 clr!ManagedThreadBase_DispatchMiddle
22 clr!ManagedThreadBase_DispatchOuter
23 clr!ManagedThreadBase_FullTransitionWithAD
24 clr!ManagedThreadBase::ThreadPool
25 clr!AppDomainTimerCallback
26 clr!ThreadpoolMgr::AsyncTimerCallbackCompletion
27 clr!UnManagedPerAppDomainTPCount::DispatchWorkItem
28 clr!ThreadpoolMgr::ExecuteWorkRequest
29 clr!ThreadpoolMgr::WorkerThreadStart
2a clr!Thread::intermediateThreadProc
2b kernel32!BaseThreadInitThunk
2c ntdll!__RtlUserThreadStart
2d ntdll!_RtlUserThreadStart

Last Updated: 02 Feb 2021 09:30 by ADMIN
Created by: Eric
Comments: 7
Type: Bug Report

when using JustMock Free in a net 5.0 app.  I am getting an Ninject exception that IAssemblyNameRetriever could not be found.  Looking at the code on github,

the NETCORE compile constant removes the line

AddComponent<IAssemblyNameRetriever, AssemblyNameRetriever>();

from StandardKernel.cs

however, CompiledModuleLoaderPlugin uses IAssemblyNameRetriever in it's constructor and

AddComponent<IModuleLoaderPlugin, CompiledModuleLoaderPlugin>();

is still included in the NETCORE version.



Last Updated: 02 Feb 2021 09:28 by ADMIN
Created by: Mihail
Comments: 3
Type: Feature Request
JustMock should support .NET 5
Last Updated: 02 Feb 2021 09:25 by ADMIN
The issue is reproducible inside Visual Studio 2017, the same tests are running normaly outside the IDE or using 2019.
Last Updated: 01 Feb 2021 09:56 by ADMIN
Created by: Maxim
Comments: 1
Type: Bug Report
I have logging class which are using everywhere.
I want to Mock this class for all tests. And i tried to use AssemblyInitialize but got problem. I have simulated this problem with JustMock.ElevatedExamples.AdvancedUsage examples:
1) Add BaseTest class
    public class BaseTest
        public static void AssemblyInit(TestContext context)
            Mock.SetupStatic(typeof(Common1), StaticConstructor.Mocked);
            // Arranging: When the static(Foo.FooProp_GET) property is called, it should return expected.
            var fakeUsed = Mock.Create<LogWriter1>(Constructor.Mocked);
            Mock.Arrange(() => Common1.Log).Returns(fakeUsed);

        public static void Cleanup()
            //clean up stuff here
    public static class Common1
        static Common1()

            Log = new LogWriter1();


        public static LogWriter1 Log { get; set; }


    public class LogWriter1


2) When run test from VS - all ok
3) When run from command line it is not working. Show Message box "Process Starts Now".

SET COR_PROFILER={B7ABE522-A68F-44F2-925B-81E7488E9EC0}
"C:\Program Files (x86)\Telerik\JustMock\Libraries\JustMockRunner.exe" "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\MSTest.exe" /testcontainer:"D:\test\CSExamples\JustMock.ElevatedExamples\bin\Debug\JustMock.ElevatedExamples.dll"

How i can mock logger for all test? It is static public property.

I use MS Test + VS 2015.
Last Updated: 01 Feb 2021 09:35 by ADMIN
I am using Visual Studio 2015, Crystal Reports 12.0.2.  When running from Visual Studio in debug mode or not, the application hangs on the statement "new ReportDocument()".  ReportDocument is a class defined in CrystalReports.

When I disabled the JustMock Profiler, this statement no longer hung.

Just FYI.  Hopefully others will see this.
Last Updated: 28 Jan 2021 15:47 by ADMIN

Hi Team,

The main site is blocked in Sweden. I spoke to my VPN provider and got the exit IP address (

They said that the IP address used to be listed as an Iran IP in older GEO IP databases, which would explain why is not working, even though it is from Stockholm

Can you please double check that your GEO IP database is not listing the Swedish IP address as being in Iran?

Thank you,


Last Updated: 19 Jan 2021 15:45 by ADMIN
Currently, JustMock extension always uses the profiler deployed by the installation, which may be different from the one deployed by the JustMock.Commercial package. This could lead to unexpected failures in the rest run and different results inside and outside Visual Studio.
Last Updated: 19 Jan 2021 15:40 by ADMIN
Trial period expiration disables the essential functionality inside JustMock extension menu, but there is no clear sign for the reason. This item is about improving this situation, by making the trial expiration explicitly and easily visible to the user.
Last Updated: 19 Jan 2021 15:35 by ADMIN
Created by: Alan
Comments: 1
Type: Feature Request
I am in the process of building an internal developer platform on kubernetes. Historically, in order to run justmock on build servers we pointed to a special location of the windows registry for accessing the DLL. In kubernetes, the build runners are kubernetes nodes. Is there a preferred way to run these tests in this environment? I can provide more details if it is helpful or valuable. Historically, we used Azure Devops build agents in this new world dotnet test is being run in Linux gitlab agents and not windows. I would have chosen linux in the dropdown but wasn't available.
Last Updated: 04 Jan 2021 15:40 by ADMIN

Update reference functionality wrongly suggests updating JustMock assembly reference and even more - detects currently referenced one as a lite version, see the screenshot below:

Last Updated: 03 Nov 2020 13:28 by ADMIN
The JustMock profiler should be added to the commercial NuGet package distributed from the Telerik private NuGet server.
Last Updated: 26 Oct 2020 15:25 by ADMIN

Integration with Visual Studio Enterprise Code Coverage does not work if the project refers Microsoft.NET.Test.Sdk package version 16.3 (and above). The test run fails with exception:

Telerik.JustMock.Core.ElevatedMockingException : Cannot mock '<type to mock goes here>'. The profiler must be enabled to mock, arrange or execute the specified target.
    Detected active third-party profilers:
    * C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\Team Tools\Dynamic Code Coverage Tools\amd64\covrun64.dll (from process environment)
    Disable the profilers or link them from the JustMock configuration utility. Restart the test runner and, if necessary, Visual Studio after linking.


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