by Dom Royko.
Thread is old, but this is the second time I've stumbled across it. And since it does not have a solution to the original problem, thought I'd add what worked for me.
My restore file was on the large side, and the following clue was in my php_error.log file:
[13-May-2013 12:33:34] PHP Warning: POST Content-Length of 9712515 bytes exceeds the limit of 8388608 bytes in Unknown on line 0
The solution was to increase the post_max_size in my php.ini file (mine is located in /etc/php5/apache2/php.ini). And restart the apache server.
post_max_size = 12M
;post_max_size = 8M
Obviously the "required parameter" error message is a bit misleading.
Hope that helps.