Common enough story: 4 x 1 TB Raid 5 failed after update. Datavolume missing. As it turned out, I had a faulty drive too.
To recover the whole array, I used a registered copy of R-Studio . Disks in REVERSE ORDER, 4th partition in each disk, Create Virtual Block Raid. Settings as below.
Start the scan and and the 3 TB partition appeared in green. Double-click that and the whole data structure was there. Mark what I wanted and pressed Recover. 10 minutes, no Linux command lines.
Hope it helps somebody.