Landscape sculpting still results in crash

I cannot perform any new sculpting on my landscape.
The landscape was created and sculpted in 4.26 without error until a couple of days ago, when I found a bit of road that was too steep and tried to flatten and smooth it.
Any attempt to perform sculpting on my landscape now results in a crash at 0% when trying to save. This happens 100% of the time.
The error it throws out makes no sense to me either.
I have tried the max LOD at -1 (default) and 1. No dice.
I have tried removing all foliage from the level (allowed the save) and then tried this tiny bit of sculpting but it crashed again at 0%.
This is the Editor’s feedback on the error:

330350-error.jpg

Here is my DxDiag
link text

Hi, are you using landmass plugin or the new water plugin?


You could try to export the heightmap of your landscape, then reimport it again. So duplicate your current level (backup), export the heightmap of your landscape, delete landscape then import the landscape again from the heightmap you’ve exported.

I’m not using either of these things. I considered copying the landscape but I figure what’s the point if in a week or two this happens again and a landscape becomes sculpture-locked. I need to know what to do or what option to change so that I can save edits to my terrain again. It takes a long time to paint after copying and I really don’t want to face the prospect of landscapes breaking and needing to be made all over again repeatedly.

It takes a long time to paint after
copying

The painting information is saved into the LandscapeLayer info files which you can access in the content browser (and which you can also export and import). So you can directly reapply them to the reimported landscape, no need to repaint.

But yeah, maybe someone can tell you why this is happening, but from my experience something breaks every now and then and sometimes you can fix it, sometimes you can’t (especially corrupted blueprints) and then you need to restore from backup (so unless you’re already doing so, you should make frequent backups, so that you’re not loosing too much of work if something breaks that you cannot repair).

Thank you very much for your help.
I have discovered that the painted foliage is the main problem. While nothing stood out as being wrong particularly, after removing it all, saving the level and restarting the editor, landscape was once again saveable.
It seems possible to me that editing landscape with foliage instanced upon it (even in a different place) might throw an error so from now on I’ll forego the urge to start painting foliage until I’m certain the landscape is finished.

In my case solved this issue deleting DerivedDataCache Folder located at :
C:\Users\psvlk\AppData\Local\UnrealEngine\Common\DerivedDataCache

Cheers

Just to add this data point here, it’s still crashing for me every time for the smallest sculpt even after deleting that cache folder.

Edit: Oh I can already update this. After you delete it, when you restart, as the landscape and shaders are re-loading, you have free reign to sculpt as much as you want. The second that the foliage comes in, it crashes. This is consistent with another thread on this issue indicating that the foliage is the problem. This suggests that a robust workaround (not sure it will ever be fixed if it hasn’t been by now) would be to somehow back-up all foliage data in a side file in some way, delete it all, sculpt the landscape, then restore the foliage data from the backup & fix anything that needs to from the foliage menu. If I can get that to work (or if I don’t), I’ll try to report my findings on it here.

Edit 2: Of course the other route is to simply keep deleting the cache folder and restarting as many times as you need. It’s time consuming but it’s robust. I wonder if there’s a way to postpone the load-in of the shaders & foliage data until you’re done with sculpting. That would be the best hack for now.

Edit 3: Scratch robust. The foliage loads in so quickly that it crashes a lot even doing this. I think if you delete a lot of the foliage on the covered area it helps.

I had been dealing with this issue after a merge from 5.0 to 5.1. and it had been driving me up the walls
I am working together with p4v and UGS and sync the game project very regularly but what is left out are the files in the engine folder.

A hint in my crashlog directed me to the EditorLandscapeResources that I had to force sync
Engine/EditorLandscapeResources/CircleBrushMaterial.CircleBrushMaterial

For me this fixed my crashes but I am unsure how to fix this problem with homegrown projects