Unable to attach ".imodel.markupdb" redline file

Good afternoon.  I have used the redline functions in an i-model with the Bentey Map Mobile app on an iPad.  I have no problems selecting the redlines and uploading them to a Projectwise repository.  The instructions that I've found state that the redline ".imodel.markupdb" file is then attached to a DGN file in the Bentley Map desktop application.

When I bring up "File > References" and choose to attach, this file format is not available.  If I choose "All files (*.*)" and try to attach the redline file, the file does not attach and the Microstation Status bar states that the file "is not a recognized file format."

I am running the Bentley Map Mobile app on an iPad (Version 05.05.02.001) and I am running Bentley Map V8i (SELECTseries 4) Version 08.11.09.836 on MicroStation V8i (SELECTseries 4) Version 08.11.09.867.

Am I doing something wrong or do these specific desktop application versions not support the attachment of redline files back into the DGN environment?  My redline file is a 2d file - I did note previous discussions that stated redline of 3d files is not supported at this time.