- How easy will it be to recover the blueprints and other assets that were in the project; can i just delete the map and make a new one but keep the old assets?
You should be able, if you can get the project to open, to just make a new umap and trash the corrupt one. All of the assets you created or imported for that map, should still be there.
If the project doesn’t open, what I would do, is create a new blank project, then copy and paste everything but the maps folder over to the new project. When you launch the new project all the blueprints and assets should still be there.
You could also try to just make a new umap in another project, copy and paste it into the folder with the broken umap and just name it the same as the broken umap
As for your second question, I don’t know. You should be able to. It may have something to do with why the file is corrupt.