UE4's Blueprints: Why do they cause crashes so often?

I think it’s just in general problematic to change anything on a variable that has a lot of references. Sometimes it crashed immediately after renaming a variable, sometimes it crashed immediately when changing it’s type and also one thing that happened to me today was that when I deleted a specific variable the next time I would right click in the graph editor or connect two nodes it would crash (I re-did it 3 times and the last I could finally save it without crashing the editor before). This is the same issue as mentioned in a comment from yesterday.
Unfortunately it is very hard to reproduce those errors or to tell how they actually occurred, since they happen mostly only on complex blueprints and also because those crashes are not consequent, as I said sometimes an action will cause a crash and sometimes not…

But I would like to help you spotting those errors, so would it be helpful if I write down the exact steps I did before a crash occurred and append log files or the error messages?

Actually, do you have an asset that is crashing that you wouldn’t mind me taking a look at? If you do, please upload it and I’d be more than happy to have a look and see what might be occurring.

Basically, I think, stabilization of the Blutprint system should have the highest of all priorities for the development team of the Unreal Engine 4.

I have put the blueprint that is most likely to crash in an empty project and it seems like it will only cause problems with all it’s references to other blueprints.

Ok now my project became corrupted…again. But I couldn’t open it even after restoring some of the latest backup versions of the corrupted blueprint. When I delete it I can open the project, restoring it when the editor is open enables me to open the blueprint and compile it, but still the editor will crash on the next startup.

Log message: Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x3f800020

How could I resolve this issue?
Thanks!

EDIT: Forgot to mention that it happened when I created a RepNotify variable some seconds before, so I believe it is again somehow caused by a variable.

Hi ,

If you are comfortable with it, I can have a look at your project and at the specific asset to see what might be going on. I am not reproducing this on my end. Also can you post the most recent logs to this page? Thank you!

Ok here is a the download link:
link text

I have deleted a lot of stuff like textures and materials to reduce the size.
It is not openable like it is (at least for me). To open it you can delete the asset from Game/Characters and restore it after load.
The most recent logs are included!

Hi ,

I was able to reproduce this crash and can confirm that it is specific to . I am entering a crash report, TTP# 242706 to be assessed by our development staff. For now, I would remove that asset from your project so you can continue working elsewhere until the cause of the crash is determined. Thank you!

Hi Fluppi393,

I just wanted to add a quick update. Our developers were able to fix the cause of the crash in the editor. However, they reported that the asset file is too corrupted to be able to be used. I would recommend removing this asset entirely.

It may make it into 4.5 but unfortunately I don’t have a solid deadline on this yet. Keep a look out in the release notes for more information!

Sounds great. Any idea when and on which branch the fix is going to be pushed to GitHub?

A pity since this crash is kind of a show stopper for me (and I’d assume for some other folks too).

I having the same issues on 4.6.1, i think i will start working in c++ cause it makes me very sad when all the stuff i’ve done doesn’t work after i load the editor again. I only started working with relatively complicated parent/child blueprint and all the problems went with it. I tried redoing most of my blueprints but i still have the issue, i need to delete my parent blueprint to be able to start the editor, i then restore it, and connect some stuff back and compile and it works fine again. Restart editor and the same error happens.

Any news on this issue ? i think i have the same problem.

Hi Raikoh,

Unfortunately I don’t have any updated information on this fix. If you could, please create a new post with your specific instance so we can see if the two are the same or if you are experiencing something different. Please provide steps to reproduce the error and your dxdiag. Additionally, if you are experiencing a crash please provide your callstack and crash logs. You can find more information on where to get each of these documents here:

I fixed this issue for about a weed now, it’s working great since then. So instead for having my custom BP as a input in my function, i just set it as an object and cast it, my child BP don’t crash on load randomly thx to that change. I came with this idea because someone was having the same problem with UMG, he was using custom widget as input and then used user widget to fix it.