Readynas 316 Volume is degraded (but all disks green)

So I have my system setup for X-Raid 5, Everythings been going good, but all of a sudden I have this volume degraded error. I have lost a disk before and it was pretty obvious that the disk had failed. But for this I am at a loss.

 

I am no programmer, but I did look at the logs, in the mdstat log it seems as though the system thinks one of the harddrives is removed, when its clearly not. Below I pasted the part Im refereincing.

/dev/md/server-0:
        Version : 1.2
  Creation Time : Sat Mar 24 08:34:42 2018
     Raid Level : raid5
     Array Size : 19510844160 (18606.99 GiB 19979.10 GB)
  Used Dev Size : 3902168832 (3721.40 GiB 3995.82 GB)
   Raid Devices : 6
  Total Devices : 5
    Persistence : Superblock is persistent

    Update Time : Thu Apr 19 15:18:46 2018
          State : clean, degraded
 Active Devices : 5
Working Devices : 5
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

           Name : 43f65fee:server-0  (local to host 43f65fee)
           UUID : 36881ec7:fe01ca74:cf066349:4dccda40
         Events : 906

    Number   Major   Minor   RaidDevice State
       0       8        3        0      active sync   /dev/sda3
       -       0        0        1      removed
       2       8       35        2      active sync   /dev/sdc3
       3       8       51        3      active sync   /dev/sdd3
       4       8       67        4      active sync   /dev/sde3
       5       8       83        5      active sync   /dev/sdf3

Anyone have any idea about this? Any smarter people wanna look at my logs and set me straight??