Why are Milestones not showing up even if the milestone criteria is met correctly??

There are occasions where milestone is not evaluated even if  the milestone criteria is met correctly

The scenario is the milestone criteria is met by the field updates of past milestone action.  For example,  there are two milestones in place.  The first one will be triggered first and subsequently change the field via violation actions, which will meet the criteria of the second milestone.    It is currently working as designed.  Milestones are not evaluated by milestone actions(such as Success Actions, Warning Actions and Violation Actions)

Resolution:
There are a few working around for this limitation

1. Manually edit and save the record to trigger milestones
2. User different criteria among milestones
3. Utilize Apex/API to update the record

chatter_answers_question_escalation_to_case_trigger: trigger body is invalid and failed recompilation: Entity is not org-accessible Stack Trace: null

Answer by Salesforce Support:

The team has been working to no longer enable Chatter Answers for new or upgraded customer orgs beginning with Summer '16 [Release notes: https://releasenotes.docs.salesforce.com/en-us/summer16/release-notes/rn_networks_chatter_answers_retire.htm ].

Some time after the release went live, it came to our attention that provisioning processes were disabling the Chatter Answers feature for existing orgs. Once the bug was diagnosed, the team was able to re-enable some affected customers through a database script, and later released a permanent fix to the issue.

The fix entailed making changes which will exclude this permission from being affected by provisioning. Furthermore, the feature permissions are now accessible for manual enablement by Customer Support.

Way to solve:
     Log a case to salesforce support