Hello, I was playing LFS normally yesterday but now it won't start. It just stop working when I start the .exe

It happens when I install the test patch

Probally security software disable install again and run.

Quote from RC-Maus :

Probally security software disable install again and run.

I don't have any antivirus software and it won't work, so now I'm using 0.6R without the patch

Which Windows version are you running?

Quote from BeNoM :

Which Windows version are you running?

7 Ultimate x64

If it is a test patch issue you should report in to the test patch thread instead of here.