Have BepInEx working, but deplying any mods whatsoever leads to it immediately crashing on startup

[EdwardTank]

And then in order to get it working again I have to purge all mods, then put BepInEx in again, and then it gives me the modded text on the lower right in the main menu.

No idea what info would be useful here aside from saying I'm installing mods using Vortex.