Every model I tried had very dark lighting. As for the map, here it is ws.q3df.org/map/pillcity/

I'm having a hard time reproducing the problem. The models do look dark on pillcity, probably due to the lighting, but they seem to be dark under both my client and the regular ioquake3 one. Did you try the test with all paks removed from baseq3 except pak0-pak8 and pillcity.pk3?

I tried with just the pak0-pak8 files and the pillcity file, and I still have the problem.
i.gyazo.com/0f6c10...c03cc4361bb.jpg
i.gyazo.com/76c2ff...c0d505e68bb.jpg
It's not just the gun model. All of the players' models are black, including mine and others. I noticed that the models have a tiny bit of lighting, but it's way too dark. I am using the vanilla game, and not UIE. One thing I noticed when I went to the maplist to load the map was that there were maps that I didn't have in my baseq3 folder, such as the osp maps, and 4 other maps called mptourney1, mptourney2, mptourney3, and mptourney4. Could this be a possible culprit? I'm thinking it has something to do with a previously stated issue, where all of the mods that are in the Quake 3 appdata folder showing up in the mod list, even if I don't have them in the game folder.

Edited 1.12 hours after the original posting.

Did you also remove files in %appdata%\Quake3\baseq3 as well, to make sure there really are no files except pak0-pak8 and pillcity.pk3 in any baseq3 folder? Also try setting fs_search_inactive_mods to 0 before starting the map.

The additional maps in the lists are normal and it shouldn't present a problem by itself.

Edited 23 seconds after the original posting.

I did everything you said, and I still have the problem. Though, when I set fs_search_inactive_mods to 0 and deleted the folders in the %appdata%/Quake3 folder, the osp maps went away, and the mptourney maps lost their picture, so they were replaced with the Quake 3 logo.

I suppose you could try deleting the %appdata%\Quake3\fscache.dat file. Or rather, just rename it to something else like fscache2.dat so there is a record in case it turns out it did have something to do with the problem.

Would it be possible to get screenshots that show the difference between the 'broken' and 'working' versions?

I think deleting the fscache.dat file fixed the issue, as I no longer have it.
i.gyazo.com/0f6c10...c03cc4361bb.jpg
i.gyazo.com/ef8c1c...fbd60160645.jpg
I also noticed that on the 2nd picture, the lighting of everything else is darker, and less saturated compared to the first picture. I'm still having doubts about the fscache.dat deletion being the thing that fixed it. If I notice it again, I will let you know.

Did you rename the file or have any other way to restore it, so you could put it back and confirm it was indeed the cause?

I deleted the fscache.dat file, and loading the game again made a new one. When I deleted the fscache.dat file, I deleted it along with all of the other files in the %appdata%/Quake3 folder, so it may not have been the fscache.dat file that caused it.

Yes, could be anything then, especially since you probably deleted the main q3config.cfg file as well.

I tried switching to the opengl2 renderer, and I got the problem again. I'm guessing that when I deleted the folders, and subsequently the config files, I made the game switch to opengl1, thus fixing my problem. The source of the problem is without a doubt the opengl2 renderer. Deleting every file in the %appdata%/Quake3 folder sped up the game, too. It is almost the same speed as when I had only around 700 maps.

Edited 1.06 hours after the original posting.

That's similar to what I'm seeing testing on a clean install. Extremely dark models with the opengl2 renderer, and still dark models but not to such an extreme degree with the opengl1 renderer. No difference between the filesystem versions. I guess you were getting a different renderer or different settings for some reason when you used the different filesystem versions, but I'm not sure why that would be if they were running from the same directory.

Either the opengl2 renderer file got corrupted, or something else did. Do you know if the renderer file you sent me with the filesystem enhancement got corrupted? The MD5 hash for both of the files are different, but I don't know what was changed.

Edited 3.57 minutes after the original posting.

The dark models seem to be normal behavior for the opengl2 renderer, so if that is the only issue I don't think a corrupted dll is a factor.

I just sent a bug report to the ioquake3 github, who supplied me with a fix. Here's a link to that thread. github.com/ioquake/ioq3/issues/331

That's great, glad they were able to solve it.

Just a quick note, if you are using my filesystem builds, I'll need to recompile the renderer dlls for the fix to work properly. If you mix the native ioquake3 renderer dlls with my filesystem client it usually runs but is prone to shader precedence issues.

Edited 30 seconds after the original posting.

Ok, I will stay away from mixing new renderer files with your filesystem.

Now I get a new error. When I am playing a CTF match with 15 other bots, I press tab and see that only 13 of the 15 bots have actually connected. When I look in the console, it says "Client 15 failed to connect!" Any fixes?

What is your sv_maxclients setting? Are you using UI Enhanced with my modifications? Are you using bot_minplayers or selecting the bots individually, and if it's the latter can the problem be tied to specific bots that always fail to load?

My sv_maxclients is at 16, and I am using your modifications with UI enhanced. I am selecting the bots individually, and it seems that the same 2 bots always fail to load. However, when I add just those 2 bots to a game, they both work.