Using the ArcGIS Enterprise Cloud Builder for Microsoft Azure, I've deployed an instance of ArcGIS Server 10.5 to Azure. Using ArcMap, I've created an image service and deployed it to this server. I got an error when trying to publish the service, but the service appears in the Service Manager.
When I try to start the service, I get the error:
This is, in fact, the correct path to the data, and the ArcGIS Run As Account has access to this folder.
The folder containing the input data is also registered with the server, and has been validated?
So why is ArcGIS Server telling me that the input data source path is invalid?
Additional information: here's what's in the logs: