I have Configured Manage Engine and was successfully using it without any Issue. For some reason I deleted a Domain Controller from the Windows Devices and then wanted to add it back, but I can't.
I am Attaching Screenshots for you Reference:
This is how the machines lookup
When I try to search the device to add it, it says no device selected as per below screenshot:
When Trying to Upload the Device
I also try to configure it manually but then it gives below error, that its a duplicate.
When Trying to add the Device
I am adding all theses device from the Domain. My Machine on which Manage Engine is installed, is also domain joined.