1. Create a dev user that has access to openshift-monitoring namespace
2. Login as dev user
3. In these testing cluster, I can see the dev user has access by default to openshift-virtualization-os-images, probably because Openshift Virtualization is installed
4. However, due to lack of permissions for this namespace openshift-virtualization-os-images or any other reason:
   1. Go To Observe > Alerting
   2. Select openshift-virtualization-os-images => You don't have access to this section due to cluster policy with Forbidden (user=user, verb=get, resource=prometheusrules, subresource=)
   3. Switch to Silences tab => suddenly namespace is changed to All Projects and you are able to see all active
   4. Create a silence => Label where Label name = namespace, we have Label value = #ALL_NS#
   5. 
   6. Click Create => invalid silence: invalid label matcher 0: invalid label name ""

1. 1. Dismiss this creation
2. Select a silence that is Active and check its namespace, i.e for AlertmanagerReceiversNotConfigured the namespace = openshift-monitoring
3. Edit this silence => Label where Label name = namespace, we have Label value = #ALL_NS# instead of openshift-monitoring
4. 
5. Recreate silence is the same
6. 

Note:

• So, not sure if it is considered a bug or a misconfiguration that originates these cascated problems.
• User's permissions:
•