Assets from alternate levels show up as (unloaded) in my main level

When I switch between the level with assets and the main level it usually crashes, this time with this error.

Fatal error: [File:Z:\UEVFS\Root\Engine\Source\Editor\UnrealEd\Private\EditorServer.cpp] [Line: 1934]
World Memory Leaks: 2 leaks objects and packages. See The output above.

I have noticed things slowing down and have had multiple memory leak crashes.