USB failed to mount

[JKey]

hi everybody,
a little problem with the potential to grow. I am away from home for some time and brought my little laptop with lite 5 installed. It is an HP laptop with only a 32gig ssd so I use USBs for storage and work. It was fine until I just came back and get the message;

failed to mount " WORK"
Not authorized to perform operation (polkit authority not available and caller is not uid 0)

when I tried to open the stick.
Today there was an update which needed a reboot and I used Stacer, that`s it. Can somebody please advise?

[JKey]

now I feel stupid ,)) logged on this morning and it works, I really did try it a lot yesterday, my little PC obviously needed a good nights sleep!