That one I can solve. ch20.rpy, ch20.rpyc, ch99.rpy, and ch99.rpyc were all phased out of my mod and are not currently present in JokerLeader's mod, either. If any of those four files are in your game folder, you should delete them, and that should fix your immediate problem.
As for some of the other errors people seem to have been facing, ch77-ch80.rpy had significant changes made to them between v0.11.02 and v0.11.03, so trying to use v0.11.02 of the mod on newer versions of the game will likely cause errors. I already have a work-in-progress build of The Roommate WT+ Mod for v0.11.03, but since a long-standing bug/error was corrected in v0.11.04, and togs hasn't released it to the public, and JokerLeader has not updated his mod for v0.11.04, the WIP build would not have the fix. Once togs releases v0.11.04 or a future build to the public, I should be able to release an updated version of my mod shortly thereafter. I see no point in trying to release a v0.11.03 of my mod at this time, but I am still currently working on updating it.