Hosted services not loading with error MapServer not found

[wizgis]

Hello Community,

We are on ArcGIS Enterprise 10.9.1 and today we discovered that all of a sudden our hosted services are not loading. 

Things that we have checked so far:

1. Validated datastore from server manager, datastore was validating
2. Ran describedatastore and it showed datastore mode as READWRITE
3. In developer tool logs error message was : Error Code 400, Service Hosted/<name of service>/MapServer not found 
4. Checked that hosted services are in started state from manager end. 
5. Checked that datastore windows service is running.

Is there anything else that needs to be checked.

Any suggestions on how to resolve this would be really helpful.

[JohnLivengood]

My recommendation is to log into the ArcGIS Server machine and open the Task Manager > Services, look for the ArcGIS Server service and restart it (right click).  If that resolves the issue, installing the patch may help with future outages.  

[Marcy_GIS]

Chiming in to say that this fixed the problem for me, we are running Enterprise 11.4 so I was surprised that this worked considering this was an 11.1 patch.

Thanks.