Simon Reap made a very useful point:
> > On 01/06/2020 11:34, Peter Alefounder via Hampshire wrote:
> > mount /dev/sdb1 /media/flash
> >
> > I can read from the flash drive, but only write to it using
> > the command line as root, which is not very convenient.
> 
> Before you get the pop-up to work again, you could try
> 
>     mount -o uid=xxx,gid=xxx /dev/sdb1 /media/flash
> 
> where "xxx" is the user/group name of your logged-in user. That way all 
> files on the drive will appear to be owned by that user, allowing reads 
> and writes from applications etc.
Thank you Simon! I've been trying to do that, but couldn't 
get the syntax right - man mount gave me the impression it 
was possible, but it could do with a few examples. I tried
chmod, which pretended to do the job (with the -c option)
but in reality had no effect.
I have tried reinstalling x11-session-utils and udisks, 
thinking this might be a USB problem: no effect. Now I 
suspect something has gone wrong with a panel configuration
file. Everything else on the panel seems to be working
properly.
Peter Alefounder.
-- 
Please post to: Hampshire@???
Web Interface: 
https://mailman.lug.org.uk/mailman/listinfo/hampshire
LUG URL: 
http://www.hantslug.org.uk
--------------------------------------------------------------