"Unable to mount [device] Not Authorized"

[Patrick Wiseman <pwiseman@gmail.com>]

Hello:

On my up-to-date testing system (288 updates a couple of days ago,
right after the new stable went live!!), an SD drive, which previously
has mounted automatically on insertion, generates the error in my
subject line.  I Googled the error, and found that this is not the
first time people have experienced the problem, but found no reliable
solution.  I was able to run blkid to identify the device and then
mount it as root to get at the mp3 file on it, so I was able to
complete the work I needed to do.  But is there a reliable fix someone
could point me to?

Thanks
Patrick