This happens when multiple Shared Parameters with the same name but different GUIDs are added from different Shared Parameter files (or copied or imported into the project by some other means).
You can easily see these GUIDs in your shared parameter text file:
One way to audit these Shared Parameter GUIDs would be to use some freely available Dynamo nodes like these:
Check Specific Shared Parameter has correct GUID
List Shared Parameter GUIDs
Get list of GUIDs for a Specific Shared Parameter Name
One way to fix these problems (without Dynamo) would be:
- Export parameter values to Excel, or copy to a placeholder parameter in each element or type
- Remove the duplicate Shared Parameters from the project completely
- Add a new Shared Parameter correctly
- Import from Excel, or Copy from the placeholder parameter values to the now-correct Shared Parameter
- Remove the placeholder parameter and values
A few key points from the RMCSG Shared Parameter post linked below:
- As discussed in the RMCSG, Autodesk has added Shared Parameters to many Revit Categories and standardized them via the Revit Master Shared Parameter file. Check out the Revit_Master_Parameter_List.xls file within the RMCSG download for details.
- AEC firms and building product manufacturers (BPMs) can use the Shared Parameters as a standard to supply additional data for families or products in a consistent manner.
- RMCSG Revit Master Parameter List serves as a minimum list of parameter inclusions
- Do not attempt to change the RMCSG Revit Master Shared Parameter List by renaming Parameters or changing GUIDs
- Create new Shared Parameters alongside the RMCSG Parameters in a new Shared Parameter file