I filed a prior ThreadLeak:

Thread leak in JustMock (telerik.com)

I think I've found another one: (VS version 16.10.31321.278)

telerik_justmock_debugwindow_service_client!Telerik.JustMock.DebugWindow.Service.Client.ServiceHostMonitor.MonitorTimer_Elapsed

Apparently, the MonitorTimer_Elapsed code is running on a threadpool thread and it takes longer than 1 sec (perhaps it's waiting on a lock?).

Another timer tick occurs and the method is called again. Eventually, the ThreadPool runs out of threads and grows by about 1 thread per second (1Mb /sec leak)

In one dump 2Gig was used (1962 threads on the same MonitorTimer_Elapsed stack frame)

In that same dump there were 52 stacks with this frame:

telerik_justmock_debugwindow_service_client!Telerik.JustMock.DebugWindow.Service.Client.ConnectionSetupServiceClientBase`[[System.__Canon,mscorlib]].get_ServiceAvailable

(this was the same item as my prior report).