Hi Dave,
I have run into the same problem.
A friend passed on a course to me in a zip file (backup) and then I made a new course with nothing in it but wanted to restore it with my friends course. it would cut down the work tremendously......however when I tried to restore it gave me the same message "a required parameter (sesskey) was missing". I am running off my local server and I have done some investigation and other discussions say I have to increase my file size in the php.ini file on the server......but of course I cannot find that file...
Did you ever get the problem fixed?
I really find this perplexing as I am sure this problem as come up many times but there is absolutely no literature on this subject.
Any help in this area would be much appreciated.
Thanks for your time.
Grant