1. Create a new blank V8 file by opening the relevant seed for your drawing and renaming it. Ensure your units and settings are as the same as the problem file. Ensure that you use the most recent seed file from your current version of MicroStation.
2. Attach the corrupted file as a reference to the renamed seed file, using Nested Reference level 1 if this has references attached to it.
3. The references to the required file need to made direct attachments.
4. Select the attached file in the Hierarchy column on the left-hand side of Reference Manager. In the main window of the Reference Dialog, select the nested files, right-click on the selected reference files and select Direct Attachment.
5. In Reference Manager, right-click on attached (newly created) file, and select "Merge into Master" Left-click in the View Window to accept the command.
6. Save the new file. This way you will have a new V8 file with a clean header and all the required geometry in it.