Help with mod problem

hey i have recently had this problem with my game that it doesn't seem to load up many of my mods it used to say that i had this amount of mods activated from 93 mods installed but now it says that i have 43 mods activated of 56 its like many of my mods just disappeared i lost most of my map mods and some of my car mods i just opend the game and everything was as normal but then i closed it to do something else and when i opend it again it was like that.