ArcGIS Enterprise to ArcGIS Enterprise collaboration
The minimum version for ArcGIS Enterprise to participate in collaboration with ArcGIS Enterprise is 10.5. Keep in mind that any participants using previous versions will only have capabilities available for that version. For example, hosted feature layers may be shared by reference only in versions prior to 10.6.
ArcGIS Enterpriseand ArcGIS Online collaboration
The minimum version for ArcGIS Enterprise to participate in collaboration with ArcGIS Online is 10.5.1.