I had this issue too, for me, it was a mod conflict. I've racked my brains to remember which mod, but alas I cannot. It was certainly a mod related to vehicle enhancement (or perhaps a pickup truck), if that's any help.
I had this issue with that vehicle shop storage mod and the major service mod. The two mods are not compatible because they use the exact same menu. I removed the shop storage mod and the repair menu worked again.
