Unity freezes on “Begin MonoManager ReloadAssembly”

I have a unity project that freezes I think randlomly on play and on compilation events. As far as I checked, could be for something related to this:

Seems that a blocked network thread persisting between playmode stop/starts could be causing the issue, but that is only my guess. I have researched about how to track and stop threads so that I can handle that when I stop playmode in editor, but as far as I checked you can handle your own thread created, but not terminate all, or check for an active one that could be producing the problem.

As the project freezes and there is no chance to debug, so no chance to check which thread is cousing the problem if any, as my project is big, my question then is if there is a clean way to stop/terminate cleanly all the active threads on the editor when you stop.

The task manager when the freeze takes place shows the CPU at 0%.

When the freeze takes place, with visual studio attached, on VS pause to check the running code (if any) showas no compatible code.

What Editor.log shows last is:

Reloading assemblies for play mode.
Begin MonoManager ReloadAssembly

Unity version: 2018.4.12

Thanks in advance for any help.

After researching hard, program cleaning and wonder about the problem, I removed Library and Temp folders and reimported the project, and the freeze does not happen anymore. Although the reason for the problem is unclear, I post what worked for me in case it can be useful for someone.