After making a configuration change in SAM's Admin > Configuration > System page the User Interface is inaccessible. How can this be reversed?
Reset the change through the database. In the example of the "Force https" checkbox under Admin > Configuration > System > Security run the following SQL query and commit the change, before restarting to turn it off again:
update system_configuration set system_value = 0 where system_key = 'control_force_https'
The configuration settings under Admin > Configuration > System are stored in the system_configuration table, as system_key and system_value pairs. To find which one of the entries needs to reset, look at the system_configuration_h table.
In there is a row for each audited change, including a timestamp in the time column, and orig_system_key, orig_system_value columns for what the old entries were. Then use that information to reverse the change in the relevant system_configuration row.