I posted the following reply on another thread, it might be of use:
I had slightly different error - Quadrant couldn't open the database file \\<server_name>\Profile$\<user_name>\Application Data\Microsoft\Quadrant\Quadrant.3.0.1803.10.<Domain Name>.<user_name>.mdf". I think this has to do with the using of roaming profiles (???).
Anyhow it seems that Quadrant was copying the Quadrant.mdf and Quadrant.ldf files from C:\Program Files\Microsoft Oslo\1.0\bin to the above location, so I created a new database via management studio called Quadrant.3.0.1803.10.<Domain Name>.<user_name>, then stopped the server and replaced the newly created mdf/ldf files (default SQL server 2008 location, ie. C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA) with the ones from C:\Program Files\Microsoft Oslo\1.0\bin. I also needed to add my AD login as a user to the Quadrant database - with db_accessadmin/db_owner/Repository... roles.