Right before someone say's make sure you're running it as admin, and change the compatibility already done that when the tools where first installed. Anyone I can compile the map i can build IWD's but when i tick build mod.ff fastfile i keep getting the error stated above "-1073741819". Now i could just reinstal the game and modtools but thats a pain and i dont really fancy trying to find half the models and textures that i already converted. Any help would be great

Installing this worked for me when i had this error
https://ugx-mods.com/forum/index.php?topic=10245.0

If that happens to all your maps try to undo when you recently did from your last successful compile. When this happened to me it would always give an error with only building .ff, and I found out it had something to do with a custom perk machines pack I tried using. When I replaced those same perk machine files with the modtools it started working again.

Installing this worked for me when i had this error
https://ugx-mods.com/forum/index.php?topic=10245.0

Tried it but still had the same error. Anyway i just reinstalled the mod tools and game again.