Can't Save Error Crashes Engine

Hello. I am working on a blueprint that places down a random decal when it is placed in the scene.

When I try to save the level, this error appears and sometimes causes the editor to stop working.


I looked for answers, but all they said was to wait for the next version. Most of the threads were earlier versions such as 4.5. Is there something with my blueprint that is causing it to crash or is it something with the engine? Thanks in advance.