When starting an UT edit session you get the following error.
Editing is not possible !
If necessary please ask your responsible system administrator.
Object reference not set to an instance of an object.
The data sources of all layers are invalid.
In this case, the data sources of the layers have to be adjusted in the map displays with the function "Switch Data Sources of all Map Views” and saved again.
This can occur, when a database is deduced from another database using the tool "Create UT database schema” or a database is setup newly from a database dump. The map displays are copied identically with the old notations to the "old” database. If this doesn't exist, the layers are invalid and shown with red exclamation mark.
Check of databases optimally via TOC > Source.