
Updated DNS2012R2 Addendum overrides. Learned a few new things with Overrides workspace views, and why Authoring pane > Management pack Objects > Overrides may not load.
When your management pack has improper overrides, expect the loading icon. This may be caused due to overrides, whether error is with target, class/rule/monitor.

Sometimes, an Object of class error gets your hopes up (pointing at a non-existent object).

Example when Overrides loads properly

If Overrides view will not load, try creating a workspace view for Overrides.
Navigation Steps:
From SCOM Console
Click on My Workspace
Right Click > New > Overrides Summary View

Select checkbox ‘with a specific override management pack’ checkbox, then the ‘specific’ link to choose management pack(s).

Choose unsealed management pack(s) with overrides
Can select all – OR pick a few to see what loads without errors
Click OK
If you get the loading screen and error, now begins the pack analysis.

Clicking on the ‘Show’ link points to a non-existent object
Microsoft.EnterpriseManagement.Common.ObjectNotFoundException: An object of class ManagementPackClass with ID 76e2559c-aaf4-b1ec-60cf-d40ab4102fbc was not found.
How did I know that?
Run get-SCOMClassInstance command from PowerShell or Operations Manager shell
Example output of ‘get-SCOMClassInstance -ID “76e2559c-aaf4-b1ec-60cf-d40ab4102fbc” ‘

Work on the Overrides of the affected XML packs, and Import.
Once corrected, the Workspace view loads successfully, finite!

Documentation
My Workspace https://learn.microsoft.com/en-us/system-center/scom/manage-web-console-my-workspace?view=sc-om-2022
Monitoring workspace https://learn.microsoft.com/en-us/system-center/scom/manage-using-monitoring-workspace?view=sc-om-2022