Thanks, Gavin and Mike.
I had to install a few more modules in addition to the one Gavin mentioned and now the old courses are accessable again, and it seems to be OK at creating new ones.
When I upgraded to 2.4.1 I did not check through the required Perl modules list in the Installation manuel -- I assumed since I had done that for 2.3 last year the ones I had would still be OK.
Thanks again --rac