Blueprints are increasingly getting corrupted (blank details panel)

I have a moderately sized project containing a number of character blueprints. recently i’ve experienced a rash of blueprints getting their components nulled, resulting in a blank details panel. Typically this happens with blueprints with custom C++ parents when i change something in the constructor. This is annoying but it’s something i can deal with. Today, however, one of my main bot classes, which i have not touched, has lost its movement component. It is based on the default Character class, so I have absolutely no idea why this is happening and it’s threatening to destroy my entire project.

It’s worth noting that this project has undergone 2 engine upgrades (4.12-4.14) although these particular character blueprints were created in 4.14

Is this normal? is there a workaround for dealing with these types of broken blueprints?