When attempting to modify group configurations on Pulse One On-Prem under Appliances > Group Configs, the group configurations are unavailable because the group configurations panel in the top left is unusable as it is in a constant state of "loading" .
This problem occurs if the master_appliance_ID value is Null. To check if this is the cause of your issue I suggest connecting to your On-Prem appliance using Chrome. Once connected go to Appliances > Group Configurations and hit F12. This will launch the Chrome Web Tools feature. Once the web tools are open refresh the page by selecting F5.
Select Network at the top and under where it says filter select ALL. In the Name column find an entry for groups. There may be more than one, you'll know when you find the correct groups entry when the field to the right is populated. Expand as needed to view the config groups which are numbered starting with 0. Expand each group and check the master_appliance_ID entry for a null value. If one or more groups has a null value move on to the solution portion of this KB.