readynas 524 stuck on btrfs delete delayed dir index

Readynas 524 x4 totaly locked up with the following display

btrfs delete delayed dir index

During incident 4 people  were working on files from the nas, with programs that periodically write back or access the file (inDesign and Revit).

Admin access was maintained throughout the incident.  However, when the logs were collected, it locked up Firefox and after that I could not download logs.  Quotas are not activated, there are hourly snapshots on two volumes, and bit-rot protection is enabled.

How can I avoid this in the future,  Will files be corrupted, if I just power down while this is happening. 

<rant follows>

I am only 30 days out of netgear support, and I have to admit, this particular unit has not given me much to complement it or have confidence.  This is my 5th readynas, and this one just doesn't seem to be up to the task.

<back to task>

This is a business, and this nas is mission critical.  What do I need to do to safegaurd data, and keep people working.

thanks in advance