UE 4.6.1 Crash on Level BP Save

anonymous_user_68f8320f · April 16, 2015, 9:02pm

Hello,

I’m updating my level blueprint as in following screen:

As soon as I compile it / save it, editor crashes with following error:

Ensure condition failed: false [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.6\Engine\Source\Editor\BlueprintGraph\Private\EdGraphSchema_K2.cpp] [Line: 2963] 
Unhandled blueprint type ('bad_type'), failed to find type description.

Since I’ve [this post][2] I’m suspecting of one variable in CPPBlueprint Actor class (namely getCustomResult function which returns double).

Function uses std::chrono::steady_clock::time_point variable internally but I’m not exposing any of that in blueprints. I have successfully used std::strings without exposing them to UE.

So I’m not allowed to use std::chrono even internally? I’m integrating external code into unreal. I just want to use STL…

Any help is appreciated.

anonymous_user_2b03d27c · April 16, 2015, 9:20pm

Hey -

There are a few questions I’d like to ask to help me investigate this issue.

Can you post log files from crash which will provide us with additional information about what is causing crash to occur?
Also does crash occur as you compile or as you save or when you do either operation?
Is screenshot from before you updated blueprint or after?
Can you also add a screenshot of blueprint from opposite state as well?

Cheers

anonymous_user_68f8320f · April 16, 2015, 9:31pm

Absolutely,

When I call it “crash” actually an exception occurs and sends me back to Visual Studio and I can’t re-open editor without stopping execution. It doesn’t close immediately. For your questions:

I didn’t find anything useful but here is log file: Log file open, 04/16/15 23:56:48LogInit:Display: Running engine for game: Buil - Pastebin.com
Actually both and neither. Whenever aforementioned function is inside level blueprint, it either crashes on its own or I can trigger it with either save or compile. Both causes a crash.
After. I managed to get a screenshot before it automatically crashed.
I can’t what you mean by “opposite state” but if I remove “GetCustomResult” function from BP (before it crashes if I’m lucky) editor does not crash.

I hope those answer your questions.

Edit: Here’s a photo after “crash”:

anonymous_user_68f8320f · April 17, 2015, 5:26am

Bumping this thread.

anonymous_user_68f8320f · April 17, 2015, 10:34am

Updating to latest version did not help.
I’m still looking for an answer here.

anonymous_user_33800a51 · April 17, 2015, 2:26pm

Hi ,

No need to bump threads here. We track issues internally so we don’t forget them. It can take time to find solution you need and find source of bugs, and we need to sleep every once in a while, too =) will get back to you as soon as he can. Thanks for your patience!

anonymous_user_2b03d27c · April 17, 2015, 2:49pm

Hey -

When you say automatically crashed, does it do so when you open level editor? Do you get same error if you use function somewhere other than level blueprint? And when I mentioned “opposite state” I was referring to whether you had changed your blueprint. If you had made changes already then I was curious what blueprint looked like before changes. If your screenshot was from before making changes that I was curious what result was supposed to look like.

anonymous_user_68f8320f · April 17, 2015, 9:09pm

Greetings,

@: I’m on a really tight schedule here, unfortunately including my weekends : / Apologies for my impatience, I know you guys have a lot on your plate as well.

As for questions:

Opening level editor seems to be cause yes. Does not crash unless I open it.
I managed to recreate same problem inside CPPBlueprint event graph by calling same function.
Additional explanation: I have created blueprint from C++ class I’ve previously created from “Add code to project” ( who’s base class is Actor class). I simply drag blueprint into level to instantiate and use it inside level editor. As such, I don’t know how to add C++ components to scene and use it otherwise.
I do not need to do any changes for it to crash. Simple presence of “getCustomResult” function is making editor crash in and of itself. If I remove function, it stops crashing. Here is code if you are wondering: // =================================================================// CPPActo - Pastebin.com

“CustomProcess” simply opens an std::thread (for a dummy function), joins when you call merge and stores execution time in a std::chrono::steady_clock::time_point variable. I’ve tried only make a simple timer which also causes editor to crash.

Regards.

anonymous_user_2b03d27c · April 20, 2015, 5:04pm

Hey -

likely cause of crash is that return type of function is double which editor doesn’t know how to handle. If you change it from double to float you should be able to use it without crash.

Cheers