After restarting the server machine, unexpected behavior may occur when connecting to WMS services based on image services.
When publishing an image service, capabilities files containing the WMS service end point URL and layer names are generated. Client applications use these capabilities files to correctly retrieve a map.
Portions of the end point URLs could change after restarting the server machine. For example, the IP address of the server machine might change before the restart is complete.
If this change occurs, the end point URLs in the capabilities files are no longer valid and the WMS service fails to draw.
When a machine hosting the ArcGIS Server Object Manager restarts, the capabilities files should automatically be deleted and re-created. The problem is encountered because ArcGIS Server is sometimes not re-creating the capabilities files for image services when the machine restarts.
This problem does not occur if an image service is restarted manually. This problem does not apply to map services.