How do I restore my webmaster rights once I have denied group access to admin?
Firstly access your xoops database through phpadmin or whatever program you use.
Go to the xoops_users table and click "browse". Note your "uid" number which will probably be "1"
You will see the "group ids" listed by browsing the xoops_groups table
Then go to the xoops_groups_users table and click "browse". Then find the row with your users id = "1". Notice the "groupid" column you should be in group "1" which is webmasters. So you are in group 1, and have a user id of "1".
If for some reason this is not "1" click "Edit" for this row and make yourself a "1" again for the groupid column.
Then go to the xoops_groups_permissions table and look for the "gpermname" column. Then look for all the "system_admin" rows.
You might find them in later pages. Edit each system_admin row and change the gperm_groupid to "1" which is the webmasters group.
This Q&A was found on XOOPS Web Application System : https://xoops.org/modules/smartfaq/faq.php?faqid=322