Use the Surface Properties dialog box to view and correct a surface disconnection error, which can occur when a surface becomes disconnected from an external file that it references.
When this occurs, 
is displayed in the Import Surface operation type on the Definition tab of the Surface Properties dialog box indicating that the item was not found. You cannot rebuild the surface. However, additional data can be added, and certain edits (those that do not cause a rebuild) can be performed.
The problem can be fixed by editing the Operation Type parameter and entering the correct path and name for the external file.