I recently bought Garry’s mod, and everything was working well for about a day, but I hopped on today, and noticed that my entire vehicles tab was empty.
I have the orange box, and I’ve tried reinstalling.
Any ideas?

Thanks for the suggestions, but I fixed it.
I just deleted the G-mod folder, then started it up.

Ensure HL2 is being mounted in the Garrysmod Options and Settings.

Yes, it’s mounted.
I tried restarting after remounting everything, still have an empty vehicles tab.

Have you recently downloaded any addons?

No, none that I’m aware of.

Rename your garrysmod/garrysmod folder to garrysmod_old, and restart Gmod, see if it continues.