I know im not a dev but im tech savvy enough to help, first off are there any conflicting addons that are causing proplems and or any script errors that show up, maybe they can lead me on to the problem.

Failed creating font 'Clear Sans Medium'!
Failed creating font 'dejavusansmono'!

Those are the main two that i'm noticing, but its also spamming

HITCHED: 0.070s
0.437s @gamemodes/jazztronauts/gamemode/lib/sh_bsp2.lua : 25
(Recommended: Call 'Yield' more often to release timeslice to engine)

I don't know if you can make any sense of this, but i'm glad someone at least responded.

I found a few more, they don't sound too good.

ERROR: database disk image is malformed

[ERROR] gamemodes/jazztronauts/gamemode/lib/sh_unlocks.lua:186: bad argument #1 to 'pairs' (table expected, got boolean)

And after trying to finish the intro again, I got this:

'c:\program files (x86)\steam\steamapps\common\garrysmod\garrysmod\download\resource\fonts\aller.ttf'
Failed to load custom font file

Also, I have tried disabling all addons but the required ones, but I was still experiencing the same issue.

From what i see, youre missing a part of the files, make shure you have the content (we forget things time to time) if its happening with all files installed, try un-subbing and resubing or better yet, just deleting the addon files themselves to force them to download again.

Now from my personal expirience ive had addons break just becouse i didnt have enough space on my computer, addons will "download" weather or not you have space for it. make shure youre computer isnt full.

I'll serch around the files to see what specific parts those errors are looking for in the mean time, if what i said before dosent help I'll look deeper

EDIT: forgot to add this part, when you reset the addons it dosent reset the progress so you need to type "jazz_reset_progress yep, dump it" without qoutes in console to do that

It looks like your database file is corrupted (gmod uses a single database file for everything, so if it got corrupted somehow it'll affect jazztronauts).

If running "jazz_reset_progress" command the above person mentioned doesn't work, navigate to your garrysmod directory and delete "sv.db".

well now i fell stupid lmao

I tried the unsubbing then re-subbing and the console command, but it didn't work, so I tried deleting sv.db, and It appears to have done the trick. I thank both of you for helping me out, and i'm glad I get to enjoy this awesome gamemode