mscorsvw.exe - System Error

Can someone help me? I have this window that keeps coming out

(I'm italian, from Italy, "Errore di Sistema" means "System Error")

If I close it, it reappears a couple of minutes later.

I know that mscorsvw.exe has something to do with .NET Runtime Optimization Service, so I tried to use the System File Checker Tool, but it didn't find anything wrong
Then I used this tool here .NET Framework Setup Verification Tool User's Guide - Aaron Stebners WebLog - Site Home - MSDN Blogs, it was suggested by an user in another forum, he said that if the return code was = 0, then my .NET Framework was correctly installed and configured, and the return code is = 0, so it seems that the problem is not there either
As suggested by someone else, I tried the .NET framework tool repair, here Download Microsoft .NET Framework Repair Tool from Official Microsoft Download Center, but of course, it too said nothing wrong
So I thought to remove and then reinstall .Net Framework, but I don't know how to properly uninstall it, since I can't see it nowhere as a simple program to uninstall, not in the default windows Programs and Features list, not using third part programs (in my case Geek Unistaller, CCleaner or IObit Uninstaller), so I donwloaded a tool that should have completely uninstall it, here, .NET Framework Cleanup Tool User's Guide - Aaron Stebners WebLog - Site Home - MSDN Blogs, but, even if it says that everything is been erased, nothing changes, the window keeps pop out, and .NET Framewrok seems to be still there

Also, not everytime I start my pc the window pops out, I tried to figure out what makes this error happens (looking for the programs that run when the window appears and when it doesn't) but I don't see difference, I always use the same programs

And when this error comes out, the start menu acts weird
This is the context menu (when I press the right button of the mouse, is the right way to call it, right?) when there's not the error message


And this is when there is the error message


as you can see the black pop menu is behind the metro window, so completely useless. and if I try to move some tile, it shows this tiny white square with a not permitted red circle


I don't know what to do, or what to try, I have a Windows 10 version updated from a Windows 8.1 System, don't even know if I can restore my pc without making a huge mess
I'm desperate

I have exactly the same problem. And I think this is related to IOBit programs (advanced systemcare, smart defrag...)
Try to close all related programs and your problem hopefully will be solved