Direct upgrades of Version 2 (V2) deployments to 12.0 are supported from 11.0 or later. To upgrade any earlier version, you must first upgrade to a supported interim version, test the deployment, and then upgrade to 12.0.
If you have a V2 ArcGIS GeoEvent Server 10.9.x or 10.8.x site in your deployment that contains multiple machines, you must remove all but one machine from the site before you upgrade to a supported interim version.
Tip:
Which interim version you use and how you upgrade depends on what other functionality and components are present in your deployment on Microsoft Azure. Read the information in the Before you upgrade section of Upgrade ArcGIS deployments on Microsoft Azure to determine which interim version to use.
Use the Other versions menu in the help to access instructions for the interim version you choose.