I've recently been told my corridor drawing is corrupt. My fear is I will cause a mess by replacing it. Is this the right procedure? Start a new drawing and associate your project to it. Data reference the objects you need (alignment, profile, surface etc.) back into the new drawing. Copy and paste your assemblies into this new drawing. Now remake your corridor. Nothing to shortcut out, so my original fears were from confusion. Had this been an alignment drawing with references to it, naming it the same as the original would not have preserved the links - Is that correct? Thanks. donn