I am unable to detach a reference file in MicroStation. I receive the message: "You cannot Detach a model from a managed model. The operation is cancelled."
Beginning in InRoads/GEOPAK/MX version 08.11.09.845, this safeguard was added. If you attempt to detach a reference in MicroStation (without InRoads/MX/GEOPAK loaded), you will be unable to do so and will receive the above message. The is due to the fact the the references likely have dependencies in the current civil model. If a user detached one of these references, (s)he could permanently break relationships in the element rules.
In order to detach these references, open the DGN file with InRoads/GEOPAK/MX running inside of MicroStation. In the process of detaching the reference you will receive the message below. Selecting "Yes" will detach the reference, but may potentially break the relationships between elements. Selecting "No" will cancel the operation.