Please use the edit button (pencil on the bottom of your post) rather than making several posts after the other, which causes people to have to scroll more (which on an iPad, which I’m currently using to answer you, is incredibly annoying) and keeps bumping this thread to the top of the forum.
Installation issue
WeMod files vanishing is an indication that your Antivirus deleted it.
- Remove WeMod from your computer.
- Turn off your antivirus.
- Download WeMod from this direct link: https://api.wemod.com/client/download
- Once installed, add WeMod as an exception in your antivirus before launching it.
Payday 2 Trainer
You can see the discussion about this trainer in the official thread for it, which is here: PAYDAY 2 Cheats and Trainer for Steam.
There is a crash that can occur, but the solution to prevent it is in one of the latest posts at the bottom of the thread.