I fixed it with someone before in the game
For /gunmods:
Open this folder
"C:\Program Files (x86)\MTA San Andreas 1.5\mods\deathmatch\resources"
Delete these folder = CITweaponstats & CITwepmods
For /vehmods:
Open this folder
"C:\Program Files (x86)\MTA San Andreas 1.5\mods\deathmatch\resources"
Delete these folder = CITvehMods
You can try to all the folders which relating to the Vehicles which are = CITvehMods, CITvehicles, CITvehiclestuff & CITvehSkins
I used to fix the empty /vehmods with this solution
"Try to connect to mtasa://s0.cit.gg and then to mtasa://s2.cit.gg." , So you can try it too