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
Am I missing anything obvious? Any suggestions welcome.