I have a 4 year old array which had a power supply failure yesterday. I went ahead and replaced the PSU and got the array back online. When it came online, one of drive started shows disconnected and it was probably due my mistake of disconnecting a drive. I reconnected every thing properly and the drive came back online. I followed instructions, started the array with 3 drives, stopped, and started the rebuild. Over the night, it stopped and the disk is now unmounted and mount button shows greyed out.
I have attached the diagnostics and would appreciate help on it. wmc-diagnostics-20210729-1001.zip