Protip: -Copy ANY_DEV_ONLY.rfm -Rename to ONLINEDRIFTING.rfm
Same result. More to the point though, having an onlinedrifting.rfm is nearly pointless, just use All Cars All Tracks.
If however you have a large abundance of mods, some of which are non-drift related and may be causing .mas loading problems, do the following: -Copy the ANY_DEV_ONLY.rfm -Rename to ....anything, whatever name you want (.rfm) -Modify the top lines within the .rfm file with any text editor (Notepad, Wordpad...etc):
Example: Mod Name = ONLINEDRIFTING_SUX
Track Filter = *
Vehicle Filter = OR: 1970 S15_SPEC_r Project_D Project_D2.0 PROJECTD_2.0 DRM PORSCHE935 BMW320T CAPRI LANCIA BMWM1 CELICAT SP_Tuner D1GP MERCEDES_190_EURO_DRIFT InitialD ILLEGALSTREET D1 AE86 Within the "Vehicle Filter =" list, which will be different for everybody depending on the mods they have installed, remove any non-drift related words/tags which are seperated by single spaces. In the example above I would remove: 1970, DRM, PORSCHE935, BMW320T, CAPRI, LANCIA, BMWM1, and CELICAT.
If you are unsure of whether or not a word/tag is related to a drift mod or not, you can check which tags are used by each mod by opening up any .veh files within the vehicles mod folder, and you will find the tags listed as "Classes =":