Am getting the crash with the #3,4 and 25 as well. Fixed the #25 by extracting it out and renaming the #24 veh and json to #25 and fixing the naming inside the vehicle file. The #25 now loads so the error is either in veh or json file.
So did the same with the Corvette 3&4 but just with the veh files. I just replaced them with ones from working C7R and they loaded in showroom & track. Strange thing is I don't see anything wrong with original veh files.