UE4(4.26) glitches out after I edit TankTrack static mesh component

[Kulagin]

When I edit TankTrack and compile in UE4 Editor, UE4 glitches out and starts to spawn my tank without the tracks:

and when I try to delete these newly added tracks, UE4 crashes:

Here are the files from this UE4 crash: https://www.dropbox.com/s/1buh36jr2ffxv79/UE4CC-Windows-B90CEF734D4C7A67D27AA0B8C42F8232_0000.zip?dl=0

It starts to happen after I create the TankTrack class, add tracks to the Tank blueprint, and edit TankTrack class: add a Throttle float to it, for example, and then compile the solution in the Editor.

I recorded a video on how I get to it exactly: https://www.youtube.com/watch?v=X70jxawoLis&ab_channel=Kulagin

It shows how I start with working tracks, create new ones, set static meshes and how then they get unset after I edit the TankTrack class, compile the solution, and how UE4 crashes when I try to delete these glitched out tracks.

Pretty sure I did everything correct, and the changes in TankTrack I do(float Throttle + SetThrottle empty function) shouldn’t even affect anything.

[DanM]

Can you test creating a brand new blueprint instead? (don’t duplicate)

[Kulagin]

Thanks, I’ll try it next time when it appears. It somehow fixed itself after one of the crashes right after I created this thread. I have no idea. UE4 looks real unstable compared to VS and JetBrains IDEs. The course is great, of course.

I also noticed that Ben got the problem of disappearing tracks on one of the other tanks, too. He fixed it by removing the tank from the world and then re-adding it from the blueprint.

And crashes on compilation from time to time, too. I get crashes at least twice as often as Ben on 4.26. I do everything exactly as Ben does in his videos.

I was puzzled with “How am I supposed to continue this course if I can’t replace the StaticMeshComponent tracks with the TankTrack classes, can’t even delete them and re-add them: it crashes?”

I guess, if people get stuck on this problem with tracks or any other, really, they should probably clone the original repo:

UnrealCourse/04_BattleTank

Find the commit of the end of the video they have problems at, create a branch there, and just continue the course from there.

[Kulagin]

Can you test creating a brand new blueprint instead? (don’t duplicate)

So I got this bug again.

I tried your suggestion but it would be too much work(80 videos at this point). Your suggestion works but I found a quicker one.

So after an hour of rebuilding the tank I decided to see when exactly the problem starts. So I reset to the end of previous video commit. And found out that it starts to appear after I edit header or cpp file of TankTrack class, but only after I hit compile button in UE4 Editor.

And then I can’t delete tracks - it crashes whole UE4 editor.

The workaround around the UE4 crash on track deletion is to close UE4 Editor, open it again and remove both left and right tracks before hitting play or compile in the UE4 Editor: remove tracks in Tank_BP right after starting the UE4 Editor.

Then I can add the tracks to tank again and reconfigure them.

I hope someone would know a quicker fix, something like deleting all temporary folders in the solution and launching the uproject file. iirc when I originally got this bug, I tried it before creating this thread and it didn’t work. Might try again later and write a message here if it works or not.

Upd. If I close UE4 Editor, delete Intermediate and DerivedDataCache folders inside the project, then open UE4 Editor, hit compile button and then Play, it has all the tracks and everything is working. Compilation takes much longer than usual because, apparently, it compiles from scratch without cache, but it’s still much better than re-adding the tracks to the blueprint and configuring them from scratch.