UPDATE:

Removed every single mod. Verified local files on Steam and some were corrupted. Took about 4 hours to download GTA V again. Reinstalled every mod individually. Same thing. Simple Trainer, Speedo, and Simple fuel are the only mods that work.

NOT WORKING:
Szabopersistance
Single Player Apartments with Office
Map Editor
Rob Fleeca
Safe Cracker
Simeon Repos

So last week all of a sudden all of my mods with the exception of Simple Trainer, SimpleFuel, and LeSpeedo stopped working. I updated ScripthookV and what mods I was using that stopped working. But they still are no longer functioning. Im not sure what transpired but I am stuck at trying to get them all working again.......

Not sure if you are still having the issue. But I had no luck with Spawn MP Vehicles. However, I was able to get them back up with this mod https://www.gta5-mods.com/vehicles/mplowrider2-in-sp

Now everything is back up like it should.

@Darkening-Demise Simple Fuel was causing the problem for me. Removed the file and rest of my mods worked fine. There is a new update for Simple Fuel but haven't installed it yet

@IGamer I had the same issue, I uninstalled all my mods and reinstalled one by one. Found that Simple Fuel was causing the crash. There is a new update for it but I haven't installed it yet. Hopefully this is what your running into.