Upgrade from 4.25 to 4.26 preview - no levels?

Hi,

I have just upgraded (copied) a project from 4.25 to 4.26. When the project opens in 4.26, all the content is in the Content Browser apart from the main Levels. I have 2 main levels, a number of lighting levels and a couple of Level Sequences. When I open the project in 4.26 the two Level files are missing.

I have checked the content folder on my computer and the umap files are there. I have tried replacing these with backups as suggested here to no avail
https://forums.unrealengine.com/development-discussion/content-creation/116965-level-missing-after-a-unexpected-restard

Am I missing anything obvious? Any suggestions welcome.
Thanks

I have just created a new empty project in 4.26. I will attempt to migrate the content from 4.25 to the 4.26 project content folder. Hope it works… will report back with progress.

The migrate failed. The .umap files are there but the level files that have actual content in are not visible in the Content Browser.
I tried creating a new level in 4.26, closing UE, deleting the .umap file and renaming my migrated one to the name of the newly created level. Same result… the newly created level is not there in content browser… I’m running out of ideas.

The datasmith plugins were disabled in 4.26 so I though, since I used Datasmith to import my content from 3ds max, that might be a factor. I enabled the datasmith plugins, restarted, same result.

Open the file in an hex editor and check to see if they were changed to .26 or not. Your conversion process could have failed.

Thanks for your reply [USER=“3140864”]MostHost LA[/USER]
There were references to 4.25 in the .umap file (viewed in the HEX editor). I manually changed these to 4.26 and got a crash report when I tried to load the project:

LoginId:72d9ef2947cc1d1b28492d9cf6806cd3
EpicAccountId:bf1c1dd001fb4fcc8d3e4db2c75e8980

Fatal error: [FileD:/Build/++UE4/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMemory.cpp] [Line: 197] Ran out of memory allocating 18446744073172680704 bytes with alignment 0

UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_CoreUObject
UE4Editor_CoreUObject
UE4Editor_CoreUObject
UE4Editor_CoreUObject
UE4Editor_AssetRegistry
UE4Editor_AssetRegistry
UE4Editor_AssetRegistry
UE4Editor_AssetRegistry
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
kernel32
ntdll

It’s interesting that the lighting levels also have reference to 4.25 but seem to load in the 4.26 editor

Ü¿Ô����++UE4+Release-4.25�����A‘È����++UE4+Release-4.25�����

I wouldn’t do that. It’s a reference. there’s a lot more you’d need to change to get it to run.

I think you manually move the whole folder back into a .25 empty project, see if they open up / convert the project again.
IF you open them they’ll be missing references… might want to just pop em in an empty project update and move them to .26 - use backups.

Not sure this will work - as I’ve never tried it. however at worse your references might get lost. if you don’t save it, they can probably appear again if available at the correct URLS