Crash when previewing Montage with custom notifies

I’ve been following along with the “3rd Person Game with Blueprints” video tutorial series made with Unreal 4.8, using Unreal 4.9. When I get to video 17 (A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums), I run into an issue where Unreal begins to systemically crash.

After adding custom notifys to an animation Montage, Unreal starts to crash when Persona begins to loop the animation. Some of the animation shows, then Unreal stops responding to Windows and I have to kill it with Task Manager. This crash doesn’t occur if I manage to pause the playback, and if I delete the notifys, it no longer crashes either. Both of those things are really hard to do, as Unreal crashes very quickly after opening the Montage.

I’ve deleted the Montage as well as the custom notify events and started from scratch, to ensure I followed the video exactly, and I have. The only detail that might be important is the fact that the skeletal mesh in use was subject to animation retargeting, as shown in the same video, but like I mentioned, the problem doesn’t begin until I add the custom notifys. Every detail of my project is identical to the one in the video. As I have to end task Unreal with Task Manager, I don’t get an error report.

At one point, I saved the asset anyway and continued the tutorial until I was supposed to see the animation in game, and Unreal crashed during the testing at the same point in animation.

Hi CarniverousSock,

I have not been able to reproduce this crash. Can you send your project in a zip file attached here, via Dropbox, or Google drive? Or you can also send it to me via private message on the forums. Also, can you send me the dxdiag from your machine so I can check for possible hardware conflicts?


Steve, thanks for the prompt reply. I’ve reproduced the crash scenario and packaged the project folder containing it, as well as my dxdiag output, in this zip folder: Google Drive: Sign-in. When I open “PunchingMontage” in Content->Character->Animations in this project, Unreal crashes pretty much immediately.

Hi Carniverous Sock,

I was able to track down the cause of the “Freezing Montage.” As you mentioned, it was tricky but once I was able to open your Montage without the editor freezing, I found you had two different slots named “UpperBodySlot” and both were being referenced by the Montage Blueprint. To fix, I had to delete the notifies so they didn’t cause a crash. Delete all slots. Then recreate the UpperBodySlot so it was the only one available:

Once this was adjusted, it has never crashed again.

I’ve been having the same issue, removed all the slots except the one and it still crashed when it hit the first notify event. Further testing revealed crash only occurs after I change the tick type to branching point.

I recommend deleting all slots, basically rebuilding the montage from scratch. If you continue having difficulty, send me your files in one of the ways described above.

That worked, had to remove all the default slots and create a new one.

Had the same problem, this completely fixed it, created a new montage and replaced the reference before deleting the old one. I only removed a couple references in my blueprints and was able to readd them easily. Thanks for the tip!