I've only ever modded GTA V once before using only a couple of replacement vehicles, LSPDFR and Rage Plugin.
I used a mods folder and it worked off the bat. I've just re-installed everything from clean in, I hope, the same way as before.. but the game only launches with the vanilla files (no problem with LSPDFR or Rage). Is there anything extra I need to do in the installation or launching process to get the mods folder to work?
Update: I've got it working but now it seems to crash almost all the time.