Hi Professor, same here.
Here is my message:
Your submission is not valid – your browser did not supply a referrer.
In order for us to validate your submission, we need to know the referring page. This information is sent over by default by Internet Explorer. Are you running Norton Internet Security, or Norton Personal Firewall? These applications will strip out the information we need. To tweak your Norton settings, please visit the related symantec help page.
If you still cannot submit your page, your referrer information can be blocked by personal proxy software, like “WebWasher” . Some users had the same problem with Manila by having Junkbusters/WebWasher to strip the referrer. Some software firewalls, for instance the Norton Personal Firewall remove the referrer. Hence such options should always be turned off.
Software like AdSubstract also blocks the referrer and makes login impossible.
The latest ZoneAlarm also blocks Referrers by default. Go to Privacy -> Cookie Control -> Custom and uncheck “remove private header information”.
Regards
Vegas Partner Support