I have a site that was built on C5 from 2012 and we initiated advanced permissions on it. The initial version was 5.5.2.1, and even though there is an update in place (5.6.0.2) it does not specify this in the system settings. So something is wrong with the updating, and the site runs really slowly. (on 1&1 shared hosting). When I have attempted to update the core in the past, I get a large error message like the one attached. Any attempts to properly update have failed (including incremental versions) and I can tell that certain functionality is missing, such as there is no way to access page defaults even as an admin.

We currently have about 300 registered users and if it comes to having to rebuild the site we want to be able to migrate their data and all the settings (theme, customizations, pages, etc.) over to the rebuilt site.

I would be happy to provide access to the account if I can find someone interested and knowledgeable on how to address fixing the problems.