windows form dont start on other machines and process can't be closed

I've got a problem with my windows form application. I wrote a simple program that can create .VTF / .VMT files out of .TGA files and can generate a .QC file and also compile this all with a .SMD file into a prop for the sourceSDK (Hammer Editor). So i can use this to bypass the incredible annoying task with compiling custom models for a map in Counter Strike.

Previously i could compile my form (same with other applications) and send it to someone so he can use it. This time it compiles normal and works fine on my system, but after i sent it to my friend it didn't start. He clicked at the .exe and his explorer.exe froze. After some time his explorer came back but he couldn't move or delete the file. He also tried to restart his system, but afterward it still refuses to delete the file and then bluescreen. (The bluescreen said something about an Errorcode = 0xc000021a)

An other friend tried to start the .exe too, but he got the same problem with the explorer ...

I use Visual Studio 2015 to write and compile my code. My target Framework is .Net 4.5.2. Does someone know how to solve this problem?

What further information do you need?

Thank you for your help Greetings Marv

EDIT #1: I think the bluescreen isn't that important for that problem. We tried it again with serveral .NET Versions and it won't work at all. The funny thing is that i sent him the whole Visual Studio project and told him to compile it on his system. The debug version in Visual Studio works fine but if he wants to start the release.exe in the subfolder /bin/release/ the same problem occurs..

Ok, i found the solution to this problem with some help from here: C# exe not starting on Win7 build computer

and here: Executing the Visual Studio created *.exe does not open a window and the process can not be terminated

He only has to turn off his avast antivirus...

EDIT #1: I found out that disabling the "Deepscreen" feature in Avast is enough to solve this problem.

Thank you for your help