once an I/O module has been persisted you cannot remove it. You probably need to reinit  please work with your local support / sales on a solution.
Hi, We purchased our unity 300 with some I/O modules pre-installed on it but as we did not need all those, decided to give them back and save money. No on the screen of Unisphere we always see  A previously configured I/O module is missing. Reboot the Storage Processors (SP) and then reseat the I/O module. And as I said reseat is meaningless cause I don't have those modules any more. So I just want to make this warning go away and tell my unity that this is removed. So do not search for it again and do not warn on this anymore.    [IMAGE] [IMAGE] :   
A previously configured I/O module is missing.