Admin retagging or deleting of tagged images intermittently gives ProGet registry UI error message

[jtraxy]

Steps to Reproduce
Create a registry with proget
Browse this created proget registry
We can see there are a few tagged images
Select one to pull from proget registry
Tag with a different name to this pulled image
Push the newly tagged image to proget
Go back to browse the proget registry with Portainer
Now select the newly tagged image and remove it

Actual Result
UI reports an error saying Unable to delete tags, but actually the tagged image from proget registry on remote side has been deleted. User can refresh the UI page, and the item is gone from UI after deletion.

Expected Result
UI should reflect the actual result

[jtraxy]

This is actually an issue in ProGet registry software.
There is no fix in Portainer itself for this - it is an external fix.
We contacted Inedo (who created ProGet) and they have release updated version 6.0.16 of ProGet on 10 June 2022.
We have applied that to the Portainer ProGet instance and the issue is resolved.

You can see the ProGet release from https://my.inedo.com/downloads/installers
The specific 6.0.16 release is detailed at https://my.inedo.com/downloads/issues?product=ProGet&fromVersion=6.0.16&toVersion=6.0.16
The particular fix is PG-2140 FIX: Concurrent PUT of manifest may yield database error:
https://inedo.myjetbrains.com/youtrack/issue/PG-2140