Ok, so yesterday i installed my g25 and now i keep getting this DI : Effect - DIERR_NOTEXCLUSIVEACQUIRED
Make sure LFS is only app running that makes use of force feedback. Close all other racing games, calibration tools etc.
Is the LFS window focused? Try switching LFS to windowed mode and click into the window to make sure it's focused. If that doesn't help, try reinstalling/updating the drivers.