a number of tiresome symptoms have surfaced on this machine in the last month or two.
as a first (i.e., simple-minded) approach, i have rebooted the machine; this took less than 5 minutes, but active sessions will have been lost.
given the nature of the most recently reported problem, i felt it best to perform the restart without a day's warning (which is what i would normally do).
Robin Fairbairns
For the CTAN team