The following error message shows up when trying to switch WP to DWP from AWI.
Release : 21.0.4
It is possible that ZDU was performed but not complete.
In Client 0, please check the parameter ZERO_DOWNTIME_UPGRADE in UC_SYSTEM_SETTINGS if it is set to Y. By default it is set to N.
In order to move forward with this issue, please check in Client 0 ->Administration -> Automation Engine Management -> System Upgrade . In which phase it is now ? Try cancelling it and see if the issue is fixed.
If it is not in any phase, please modify the value of the ZERO_DOWNTIME_UPGRADE to N in UC_SYSTEM_SETTINGS. Once done, please stop and restart your AE system.