Cheat Engine

[Corruptor]

Not precisely sure if it belongs into this subforum, correct me if im wrong.
Well, got a game from microsoft that seemingly fights off the windows debugger; using the VEH Debugger instead worked though. However, when i use the find out what accesses function on any value in the game, nothing will ever happen, no instructions will be caught at all.
This also happens with other debugger programs (tested MHS), so i guess its something about the game rather then about cheat engine itself (which is why i write this into this subforum). Anybody knows this problem and maybe some way to fix it?

[Dark Byte]

Go to debugger settings and check the "Override existing breakpoints when setting a breakpoint" checkbox if it isn't set

big chance the game will crash though, but with luck you might get some data before the crash. (running the game in windowed mode gives you the most chance)

Also, go to memoryvew->view->threadlist.
There you can see why it won't work (e.g all debug registers are used up)

and view->debug events can show you which threads make use of them more than others.
Now, if you know which threads make use of them, select all threads except those, and choose "Clear debug registers"
With luck the game won't crash too soon (it will eventually crash when those threads do trigger the anti debug check, but it happens less often)

[Corruptor]

Tried to take a look into the Threadlist, but except for one little thread in the end that is seemingly immune to GetThreadContext(), none of the listed threads to use any debug registers. The Debug Events window also stays empty all the time.
So i thought "if no debug register is in use, then im on the safe side clearing them anyways", but clearing, just like the option "override existing breakpoints", do not have any effect (they also dont crash the game).

Now, but if the variable is written into the registers correctly, shouldn't they throw debug events showing up in the Debug Event window whenever the variable is changed? kind of confused at this point

[Dark Byte]

Check the first two threads for debug register usage.
Also, a second reason why debug registers don't trigger is if it is written from another process.(Does changing the value even have any effect in the game?)

[Corruptor]

First two threads dont use them either, just like the rest. at least i never caught them having a debug register containing something else then 0 or the value i used "find out what writes to this address" on.

Debug Event list is also quite empty. A little "EXIT_THREAD_DEBUG_EVENT" with a pid that doesnt exist anymore (no shit sherloc) poped up, but i doubt that this could have to do with it.

Also, changing the value in the cheat table works perfectly and does have the correct effect in the game.

[justa_dude]

I saw this recently in X-Com: EU. The game is built on the Unreal Engine, but it uses easyhook for some reason. I'm not sure what's going on, but the debug registers are all getting eaten up. Clearing the registers seems to work, and I've not yet experienced a crash as a result.