This should not be marked resolved. This is driving me crazy in 4.13.2. I keep losing all of the configuration of blocks within my knock-down-the-blocks levels. I have repeatedly had to reconfigure all the blocks in my levels for no reason! GRRRR.
's workaround steps have worked for me so far. Compiling a blueprint that has configured instances in the currently-open level is dangerous! My simplified workaround (based on 's info below) is 1) Save level before working on blueprints, 2) After working on blueprints, restart engine without saving level.
Prototyping productivity is really crappy now, what with the need to shut down and restart the editor between every blueprint change.
I voted for UE-37428. I’m sad the target fix is 4.15. That’s a long ways away. Seems like blatant data-loss would be hotfix-worthy.