I've run into this problem several times now - I copy an assembly which contains equations (equations which contain references from a part dimension to a global variable defined in my assembly) - rename it, and rename parts within the assembly, in SolidWorks explorer. I now get a RED tree. OK - go into edit my parts, edit equations, reset references to the new part or assembly names because they didn't update with the rest of my reference changes done in explorer - problem should be solved, I would think. NO, I still get a RED tree, red equations folder. All my equations have a green check mark next to them, and they calculate OK. Display errors dialog box shows all my equations as referencing deleted dimensions, which they don't. Anyone else had this problem - Is there a cure ? Or am I just doing something stupid? Thanks - Sean