Problem

When trying to open a StormCAD, SewerCAD, SewerGEMS or CivilStorm model, the following error message is generated:

ArgumentException: Adding Duplicate

The model will then not open.

Solution

This issue can occur if there is a problem with how the hydraulic model data is stored in the database file. There are a couple things that you can try.

First, close the model but leave the program open. Go to File > Database Utilities (for V8i versions, go to Tools > Database Utilities). Browse to the database file associated with the model and select it. When prompted, choose the option to purge the database to save space. Then open the model and see if the issue still occurs.

If it does, open File Explorer and copy just the .stsw and .stsw.sqlite files into a new folder. This will disassociate the main model files from the supporting and output files. Try opening the model from the new folder location to see if the error still occurs.

If it does, try importing the database file by going to File > Import > (product name) database. This will import the model data into a new project. If this works, you can save the file to create a new model file. You would need redo any element symbology or reload any background layers.

If the still occurs, another option you can try is to restore a backup of the database file. You can find the steps to do that at this link: Can I restore a backup file of my model project?

If that doesn't help or is not possible, please contact Bentley Technical Support for further assistance.