I'm very familiar with the "Group instances of the same type do not contain identical members. Press "Fix Groups..."" error that Revit often throws up. "Fix Groups" means "destroy groups" and is never an option. Usually it has to do with groups that have members deleted, have nested groups or other complicating factors. But this one has me stumped. I just want to extend this line to the wall, but doing so throws up the error. Even if I delete the line and draw a new one, same error. What could be causing this? TIA for any ideas.
