Why can't my registered users post in the forums, or log in, or add other information to the site?

If you have users on your own site who cannot post in forums or add other information to the site, it may be due to their firewall or some other software that is blocking the referrer information. You can turn off the referrer check in the XOOPS code to solve this. Or (recommended) you can issue instructions to the users to change their firewall settings.

For more details about these issues, see the question: "How do you disable the check for referrer information?" in the Cookies and Firewall section.

This Q&A was found on XOOPS Web Application System : https://xoops.org/modules/smartfaq/faq.php?faqid=311