"Reset to Factory defaults" takes the system all the way back to the state it would be in if just installed from a downloaded image file. Since you can not currently view the current configuration or access the page that would allow you to download it to a file, this will all be lost and have to be recreated from scratch by hand.
I'm not sure if the following is supported in version 1.235, but you should try it and see. If it works, you should arrive at a page where you can re-enable all the page views that were disabled by the previous admin.
http://monowall-IP/system_groupmanager.php or
https://monowall-IP/system_groupmanager.phpNot sure if the current username and password that you know will allow you into this page or not, if the page even exists in version 1.235.
You might also try to reach the page that allows the configuration to be downloaded.
https://monowall-IP/diag_backup.php or
http://monowall-IP/diag_backup.php or
The resulting file would have to be cleaned up in an editor to remove the content that disabled all the page views, and then restored to get control back without erasing the rest of the configuration.
If you have to go all the way back to Factory Defaults without having a copy of the configuration file available, you may want to consider starting over with version 1.33.
Good luck and my apologies if any of the above is not correct. Trying them won't break anything though.