Cheat Engine

[MErtHRMKsE]

I can't debug threads I created with the VEH debugger ( int3 instructions ). It works fine with the Windows debugger, though

[Dark Byte]

veh debug doesn't currently support instant thread creation following. Only polling (which is the only option you can choose)
Normally this is no issue as most game mechanics are done from a thread that isn't constantly being created/destroyed, but in your case (creating a new thread) it is an issue.

If it's important to do this, then add a sleep for a few seconds at the entry so the thread poller has time to detect it and add it to the list of threads it expects

[MErtHRMKsE]

Quick question, is it possible that the CreateThread function in autoassembly might fail? I have this function that I use CreateThread on, but sometimes, very rarely, the program crashes. I know it is very rarely, like 1 time in 15, but it still happens. I set a breakpoint at the start of my function and ran it until I crashed. I was able to go to the "ret" of my function and then I pressed F9 and it crashed, so I don't think my code is wrong?

EDIT : Just so you know, this is completely off-topic. This doesn't have to do with anything about VEH debugger. I actually used the Windows debugger when I did this.

[Dark Byte]

It depends on your code and what it does.
If you call code of the game it could be a multithreading issue. (E.g. the main game thread suddenly reads deallocated memory because function a rellocated a memoryblock while function b was using it))

Also check the stack. Some calling conventions don't clean up the stack in case of errors. So check if the final ret returns you to the terminatethread exit call

[MErtHRMKsE]

Yeah, the return address at the end was the good one. It might be the "multi-threading" error you're talking about, I'm going to look into it