Resolve errors with empty .psg files. 
 When opening a legacy .rvt file or when adding sheets of a new .rvt file to a legacy .psg file, you may get an error stating the following:The specified XML file is invalid. Its scheme is not supported by the Plot command. Please select a valid plot list file.  
This error means that the .psg file is empty and has no XML in it. Follow these steps to fix the .psg file: 
- Open Vault Client. 
 
- Locate the PSG file that generated the error. 
 
- Click the Plot icon to open the Plot Manager. 
 
- In the Plot Manager dialog, choose the Vault location of the PSG file. 
 
- Click OK and close the Plot Manager dialog. 
 
- Refresh Vault to see that the new version of the PSG file is created. 
The missing XML is now included.