For me this issue seems to be between my HUD and my Player Controller blueprint. I add the HUD in my Player Controller, but in order to access player attributes such as health within the HUD I also need to access the Player Character. I thought the issue with due to health in the HUD, but I removed that function and I’m still getting a lockup. But that’s the Player Character, not the Controller - I made the mistake of thinking that was the circle, but it isn’t. The Character does access the Controller to get the HUD and add things to it
The most frustrating part of this issue is that it doesn’t exhibit or indicate an issue when compiling the blueprints, and the game works fine - but then when I restart the editor it locks up. I’m not even sure where the issue is now, as the only access within the main HUD widget was in the health, but the lockup still exists - so it must be in some sub-object.
The only solve for me seems to be to remove the HUD asset from the project directory to start the editor, then re-add it to the project and fix all the broken references manually, which is pain. It’d be nice if Epic added a check and indicator for this type of issue. Even something that detects the issue on startup and disables an asset so that you could start the editor with an error message with be a big improvement. I’m not sure if this is addressed in later versions, but I’m running 4.20.3 and you guys were having the same issue with 4.12
It seems that I’m adding the HUD incorrectly, I know other people add it in the game mode, but in the Testing Grounds project we started with it added in the PlayerController, so I’ve just continued that, but I’m expanding the project and now that’s causing issues. I’m not sure how to access the HUD asset correctly to add other UI elements without running the risk of these circular references. This is super frustrating and really makes me dislike blueprint even more.