I found this helpful readme from the game folder itself that shows you how to reset your game entirely when you get the black screen on start up or when you get a oddity that effects not just a save file but the game functions entirely. Here it is as following:
save games and config files are in these folders, depending on your operating system.
WINDOWS: C:/Users/[username]/AppData/LocalLow/Ludeon Studios/RimWorld
(On Windows, the AppData folder may be hidden.)
MAC: Users/[username]/library/cache/Ludeon Studios/RimWorld
LINUX: /home/[username]/.config/unity3d/Ludeon Studios/RimWorld
Deleting config files will reset them. This can be useful if the game is borked and won't start.
For debugging and troubleshooting, the output_log.txt file is in the _Data folder in the game install folder.
Why is it like this? Modern operating systems separate changing data from program installations for several reasons:
-First, it allows different users to have different save and config data.
-Second, it enhances security, because it allows the program to run without having permission to write to disk anywhere outside its own little save folder.
