General Single practice races don't load properly from Content Manager, but do from Steam.

[RacingBird1472]

[RESOLVED]
Hello! So, after I replaced the AE86's engine sound with an R34 GT-R V-Spec's engine sound, some things started to happen:

As mentioned in the title, single practice races aren't loading correctly when I hit "Go!" in the bottom right. I get sound, and the window pops up, but it's invisible, and I can't really do anything but use Alt+Tab to close it. EDIT: Now solved, thanks to a crash in the server menu lol.

I also think it happened after I used the "Reinstall current version" button in the Custom Shaders Patch's settings. I thought this would fix the issue of lights not being bright enough. (The projected light is bright enough, but the housings themselves are barely dim enough to see. Now they just don't work anymore.)
EDIT: Also now fixed, had to turn on post-processing.

I've done the usual log-looking, but haven't really found anything useful that would help me find out what's going on. Except for something in:
Documents\Assetto Corsa\logs\errors.txt
INIReader: content/tracks/c1/c1/data/lighting.ini > KEY_NOT_FOUND: [LIGHTING] SUN_HEADING_ANGLE

Anyone want to help me find out what's going on? Maybe helping me look for logs that contain specific error information relating to the above issues, and any fixes.