Unable to access file Disk write protected

a2zitsupport wrote:

Please suggest how can i resolve the read only error in NAS, or please share KB so that we can move forward

Did you read my PM? 

There are multiple problems, and as a result the NAS mounted your volume as read-only.  These include

• one disk that is generating errors
• the bit-rot detection feature is finding several files with errors that it can not correct
• a ~95% full volume, so you could also be dealing with free space exhaustion.

As I said at the end of my analysis:

The best strategy (though expensive) is to 

1. back everything up (if this hasn't been done already.
2. replace the failing disk (and consider expanding the volume by getting two larger disks and replacing another disk 
3. do a factory default and rebuild the NAS
4. restore everything from backup (making sure the volume has at least 15% free space).

On the failing disk - be sure to check the serial number.  The NAS logs sometimes number disks starting with 0, and sometimes number them starting at 1.  The numbering I used in the PM was starting from 0.