I've upgraded form 10.5.1 to 10.6.1 and I've lost all map services, even the default world cities. I've confirmed that the site directories are set up correctly and the files still exists in the same location as before. Directory permissions seem correct. Not sure what else to check?
You're missing the ArcGIS Server License. This is how it looks for me:
Licensed Role: GIS Server Advanced, Image Server
Expiration Date: Never
Software Version: 10.6.1 (build 9270)
I figured it out. When you run the ArcGIS authorization utility, it shows you the Authorization Number (ECPXXXXXXXXX) number that it reads from the provisioning file.
The problem was that, by default, the utility was reading the wrong Authorization Number from the provisioning file. It was reading the Image Server Authorization Number to authorize Server instead of the Server Standard Authorization Number. Once my GIS POC sent me the screenshot showing the two different numbers, I realized what was happening and changed the ECP number to match Server instead of Image Server.
Thank you guys!