Level names missingSometimes level information may be missing from a file, while the elements still have different level ID's.http://communities.bentley.com/products/microstation/microstation_v8_2004_edition/w/microstation_v8_2004_edition__wiki/technical-bulletin-duplicate-level-tables-tn.aspx details some possible causes and steps to resolve. These steps don't always restore level information completely.
Follow technote, then try new levelsWhen the steps from http://communities.bentley.com/products/microstation/microstation_v8_2004_edition/w/microstation_v8_2004_edition__wiki/technical-bulletin-duplicate-level-tables-tn.aspx are not sufficient another possible, partial solution can be to create new levels for the missing ones:NOTE: STEPS BASED ON PERSONAL EXPERIENCE - MAY NOT WORK - TRY THE FOLLOWING ON A COPY OF THE FILE
There should not be any elements with invalid level ID's left.Now all elements are redistributed over the different new levels. This at least makes recreating the original level table more easy.