I have submitted the ColorQube_9301-9303_system-sw#07218021630801#.DLM file via the web browser to upgrade software of ColorQube, For the last hour The printer says:
The device is not available
The device is entering SW upgrade mode. ALL jobs will be cancelled
One or more queued jobs need resources
How long does the upgrade take ?
Model: ColorQube 9303
20 minutes minimum, 1.5 Hour maximum, variance in time depends on the firmware that is current vs what it is going to, and speed of the network between PC and MFP and if an Antivirus/Firewall is not disabled first, it can wreak some havoc.
Delete the jobs in the queue, failing that you would need to reboot.