System Tree is not loading in OnGuard Monitor web application

Symptom

After logging into the LenelS2 Console application, select Monitor then Hardware Tree. The cursor spins and the System Tree never loads.

Launch developer tools in the browser (F12 on the keyboard).
Select the Network tab and try loading the page again.
If you see a red error that shows 403 – Forbidden, select the Export HAR option.
After export, select the Import HAR file option.
Look for any red errors that indicate what you need to update. In the example below, you can see that the error was caused by Logical Source permissions.
Log into System Administration > Administration > Users.
Navigate to System Permission groups > Additional data sources.
Verify that View access is enabled.
Then verify that View access is also enabled for OnGuard Policies.

OnGuard (all versions)