We need those files when it happens. The blueprints team has been making a test bed for REINST errors and each time a new case is found we add something to be tested in the future. So don’t just delete and start over, send us the project so we can figure out what’s missing and fix it 
We’re working on the dependency issue with UMG blueprints; we’ve been making careful steady progress with the circular reference problems. We think we know how to fix the dependency recompiling / reinstance problem with UMG, at least the main one, but we have to make sure we don’t break something else in the process.