Editor becomes unresponsive when certain class blueprint is open

The editor becomes unresponsive when the player character blueprint is open in a certain project after a variable amount of time, not in response to a mouse over or click but just on its own. The editor stays unresponsive with no crash messages thrown, I end up just killing the process with Task Manager in the end. This has happened more than a dozen times and persists after rebooting windows, closing all other applications etc. This happened in version 4.7.6 originally and persists after opening a copy of the project in 4.9.1.
In trying to replicate the bug I find that this has only happened when I have the player character blueprint window open. Also, this started happening after I used the set and get Post Processing Settings Nodes so I’m not sure if it is attributable to that.

Okay, after a bit more poking around trying to replicate the editor freeze, I can get the editor to freeze fairly consistently immediately or soon after clicking on or marquee selecting one of the three Set Post Processing Settings nodes in the class blueprint. So it seems like that’s the culprit. But there’s no log output that I can submit here, just a “program not responding” condition that doesn’t resolve.
Should I upload the project somewhere?

Another update, I believe I was actually using the node incorrectly. I’m pretty sure incorrect usage shouldn’t have resulted in a crash, but I’m now happily using another set of nodes to do what I wanted to do. You can mark this case as resolved if you like.

Hi ag858 -

Can you post a screenshot of the offending node and set up you are using in 4.7.6 and in 4.9.1? I know that there was an issue with the Post Processing Node causing a Video Driver crash, but this was a new issue specific to 4.9. If you could also take a look at the Windows Event Viewer and post the logs that windows generated when the engine crashed for you.

You can use this wiki for reference to using Windows Event Viewer:

Thank You

Eric Ketchum

Okay, here’s a couple of screenshots. Selecting one of the two Set Post Process Settings nodes in the middle of the screenshots gives the most immediate freeze. I no longer have the 4.7.6 project in the same state so these are from the 4.9.1 copy. I’m having a bit of trouble locating the error that coincides with the time of the freeze in the Event Viewer but I’ll keep trying.

Hi -

Okay so I ran a quick test on this one and did not get any freezing or stalling. Let’s rule out some fairly easy possibilities, can you check your Video Drivers and make sure that they are up to date and once that is done, post your DXDIAG here. Continue looking for the Event Viewer logs, but if the engine or windows never fully crashes then it might not have inputed any information into the event viewer. Finally it would be helpful if you could migrate your First Person BP into a clean FP BP Project and upload a copy here for me to test the actual setup

Thank You

Eric Ketchum

Yes, video drivers up to date in Geforce Experience and I’ll do the migration thing next.

clean project Dropbox DL link (broken before, should be working now)

Hi ag858 -

Your test project does not exhibit any abnormal behavior for me. At this point I am fairly certain that the issue has to be a logic chain somewhere causing some issues. I might need the whole project to continue debugging the issue. You can link it here or via the Private Message on the Forums.

THank You

Eric Kethcum

Freezing project Dropbox DL link

Hi ag858 -

Thank you for your help and patience in tracking this down. I can confirm that we have a bug report, UE-20336 for reference, for this exact issue causing the hard freezes for Windows 10 machines, in earlier versions of Windows it merely turns off the AERO theme on your desktop and reverts you to Windows Basic. I have added your new information to the report and as we investigate a solution I will keep you informed here.

In the meantime, it is not the marquee selection which is causing the freeze for you, but hovering over the Post Process settings node and the tool tip firing off, so while we are working on a solution for this issue, if you need to move those nodes, try to select them only from the title bar of the node itself which should not fire off a tooltip and cause the freeze.

Again Thank You for your help -

Eric Ketchum

No bother, awesome, thanks.

I am getting this issue as well, on windows 10. Definitely that. So I’m glad to hear that you guys know about it! :slight_smile: