After working for a couple of hours on a blueprint file, everything was going smoothly and I decided to restar UE4. When trying to open project UE4 just crashes and turns out that only way I can get it to launch properly is to remove manually blueprint file I made, which makes me think it got corrupted or something like that.
I’ve made important progress on this file and I really need to know if there’s a way of recovering it, this is clearly a bug related to UE4 and I seriously need a solution.
Would you happen to have Blueprint file still in your project folder or Backup folder that you could attach? Otherwise, can you tell us last steps you recall prior to your restart which we may then try to use to reproduce issue?
This also happens to me, seems like it is related to interfaces in Blueprint. I have an interaction interface, and when it is called from player character blueprint it works, but editor crashes every time I try to re-open it. If I remove interface, it works again, and if I put interface back, but remove call to interface’s function, it works… However, this only happens when I have logic in a blueprint that calls an interface function, not when I have interface just sitting in project.
If your blueprint utilizes an interface, make sure that all files referencing that interface (ie: calling a function in interface, etc) have interface added in their Properties tab.
Found problem. Calling an Interface function from a blueprint w/o adding interface to blueprint causes UE4 to crash next time it is opened. Add a compiler error maybe?
I have experienced exactly same problem. Also while working on an interaction interface. I am not very professional when it comes to coding, but it is interesting to point out that whole logic works without any errors, until I try to re-open my project - this doesn’t look like I messed it up ;-). Interfaces seem to be a bit buggy atm. Also renaming and/or adding/removing inputs and outputs from an interface, disrupts whole blueprint jungle. I am on version 4.1.
I am really stuck with this problem that UE4 is crashing on startup as long as my BP_Interface is there…
I included two pictures of all graphs in question. I have been trying to create a simple inventory system. My interact-logic itself works. I shoot a ray which calles interact-interface. For simple things like lightswitches I just create an event from that interface. No problems.
Now with inventory system I have problem that, although everything works fine in editor after I set it up, engine would crash when I try to load my project again.
In my specific case I am not sure whether I should implement interface in MyCharacter or not. According to Axtel Sturnclaw UE4 crashes every time when a blueprint that hasn’t appropriate interface implemented calls or messeges interface. In my case MyCharacter does send a message to interface. But when I try to implement interface to MyCharacter I cannot compile AddItems-function in MyCharacter anymore (Event node (none) is out-of-date. Please refresh it.)
I don’t know if this is a bug, or if I am just doing something wrong but right now I am completely blocked by this. Does anybody have an idea how to work around that?
I finally found out what corrupted project in my case. It was input for interface blueprint. Whenever I add an input and set it to myCharacter, project will crash next time I try to load it.
Actually, that happens when you have a function in your interface that takes a variable of same class as one of classes implementing it. Remember ‘Event node (none) is out of date’ error? Try dragging in event for function you created. If it passes same class as BP you are in, error will change to point to that new event node.
issue you are reporting likely has a different cause from one reported in this thread. Please open a new post in Bug Reports section with this information, as well as information requested in this post:
