So i just solved this myself. Turns out i had my SDK point to an old version which was not updated anymore. (Steam only seems to maintain one location of a game if you have the game downloaded in multiple storage locations)
Setting the SDK to “Revert to Default” fixed it.
To prevent this in the future, a “Hey, you are using an old VRC version. Are you sure?” would maybe have helped, but this is primarily my pure incompetence that caused it.