EU4Editor.exe disappears after running it

Hello everyone. I’m trying to build the editor from source, but I keep getting the same problem.

After I download the source code (zipped or from git hub), I run setup.bat and GenerateProjectFiles.bat
Then open the UE4.sln in the VS2013 Community (or Express) and build it. It builds succesfully (in both).

Then I go to Engine\Binaries\Win64 and run UE4Editor.exe. After few second an Error pops up, saying that file couldn’t be found and UE4Editor.exe disappears.
If I build the solution again it creats the UE4Editor.exe again, but if I try to run it, it disappears again.

Same thing happens if I press Local Windows Debugger. After few seconds it shows an error that file couldn’t be found and file UE4Editor.exe vanishes.

I’m using Windows 8.1 and trying to build UE 4.6. I was able to build and run a previous version of UE4 (I believe 4.3) on this machine successfully before.
Full reinstall of the Editor or source code didn’t help.

No clue what to do now =\

I once had a problem where my anti virus software deleted the exe as it thought malware was establishing itself. Any process that created an executable file was frowned upon… I think it was either avira or avast that i was using at that time…

PS: just had a jolt of memory: McShield was causing back then …

Thanks a lot, that was exactly it! I forgot I had Avast in no notifications mode, so had no idea it was blocking it =)

I switched from Avast to Malwarebytes just because of the numerous false positives regarding UE4.