"System busy" for 4 days during EX4 RAID 5 disk upgrade

I am trying to upgrade 4x2TB RAID 5 EX4 to 4x4TB. MyCloud prompted me to replace disk 1 with red light which i did. It took 15 hours and finished. Now it is prompting me to replace disk 2 with a red light. I swapped disk 2 and continue. System now displaying “System busy, please wait” for the last 4 days. All lights are flashing blue lights. What do I do now? If I restart my EX4 at this time to retry, will I lose my data?

It seems like system is initializing and rebuilding the RAID as you swap 2nd drive in the enclosure.

You can contact WD Support for the issue from the link given below:

raid is not a solitary solution. you need to backup your raid. aack. I have 2 nas and a das backup. with the WDD as the 2nd. slow slow slow.