Thanks for the reply.
I installed the optional printer drivers from the Tiger installation DVD, restarted the computer, which took longer than I expected, so I forced it to restart, and it still took a moment before it gave me the users screen. Then I tried to add the printer, which failed with the same error, then I tried an additional Epson driver with an identical name which appeared in the popup menu for drivers.
Then it installed. Then it worked.
I don't know if that additional driver was in the popup before I did the optional driver intallation.
DC