I get the below error while trying to add a previously configured Virtual Disk to ESXi 4.1 Host. Please Help.
Welcome to the Communities,
Check KB2001218 and see if its relevant to your situation
It probably happened because of the disk format.
You can import the disk to be compatible on a ESX host by using the below command (login into the esxi via techsupport mode or ILO)
vmkfstools -i <ProblematicDisk> <AnyName>