Just a follow up of what worked for me.
Tried the above recommendation but it did not work.
Removed one original HD and placed 3 new HD’s in and let rebuild raid 01 mirror.
Swapped out last remaining HD with 4th new HD
Reset to factory defaults but the unit became unresponsive. All green HD lights but no power light and could not connect through browser or detect using WD Discovery or WD Link.
Replaced original 2 HD’s and removed all new ones. The raid rebuilt and all was back to normal and could log in.
Here is what worked.
Left in 2 original 1TB HD’s and added 2 new 2TB HD’s
Built Raid 01 mirror and ended up with a 2TB raid mirror (the SharSpace was always going to use smallest HD size)
Removed another 1Tb HD and turned unit on, logged in and all HD’s showed Good.
Removed 2nd old 1TB HD and replaced with last new 2TB HD
Same problem as before so replaced last old HD again and could log in again.
Built a raid 01 (2 mirror mode)
Turned unit on and could log on.
Removed last 1TB HD and replaced with last 2TB HD ( now a total of 4x2TB HD’s)
Turned unit on and was showing all HD’s as Good.
I clicked the option to clean all drives under WD Storage Manager. (may have only given me the option to clean 3 HD’s I think)
Built a raid 10
Also I when I ordered the EARS HD’s the supplier upgraded them to the new EZRX drives as they had none.
So I can confirm that the newer EZRX HD’s work…so far.