When trying to add a sheet to the Sheet Index, the Add Sheet dialog does not show any sheets in the selected DGN file?
A sheet model can only be added to one Sheet Index at a time. Therefore, if you have received new sheets from another user or another project, it may be necessary to remove the current Sheet Index assignment.
To verify which Sheet Index your DGN is associated, go to the Sheet Properties and look at the Sheet Index field in the Sheet Properties to see which DGNWS the sheet is associated to.
To change, first remove the Sheet Index association by running the key-in: sheet removefromsheetindex [sheetname]
Note: If the sheet name contains spaces, the name should be enclosed in quotes.
Once the association to the old Sheet Index is removed, the Sheet Index field will now show "Not in Sheet Index"
Now the sheet will be available to be added to any other Sheet Index.