Modified blueprints compile and run as expected, but editor instantly crashes upon restart, what to do?

I’ve been editing some blueprints, and they behave as expected in-editor. When I play the project, the new added functionality works.

However, as soon as I close unreal editor and attempt to reopen it, the project instantly crashes (usually at around 93-95% loading). If I discard the changes from version control, then I can open my project normally again (without the blueprint changes).

Deleting all folders in the project directory other than Content (i.e. Config, DerivedDataCache, Intermediate, Saved) lets me open the project with a default level. If I try to open an actual game level, the project crashes.

If I validate the content folder, I can open game levels again- but they don’t work properly, and the message log spams me with blueprint runtime errors. Reopening the project and then the level again just results in another crash.

Here are some of the error logs that get generated (seems to vary per crash):

Any idea what could be going wrong? To be clear, everything works exactly as expected until I close the project (even if I save all before doing so). Then when I try to open it again, it crashes.