Taking over maintenance of another Joomla site can be either very easy or leave you scratching your head.
For instance just today I logged on to the Massachusetts Orthoapedic Association administrative area. Everything was in order and the latest versions of Joomla was installed, great start so far.
The first problem I encountered was every time I would check one of the installed components I would get an error related to the cache_file. Well this is one I never seen before, even after 10 years of maintaining dozens of sites.
So I logged into the hosting company via cPanel and starting reviewing the folder/files looking for anything that should not be there or didn't look right. After my first review everything look normal. So I went to the most important file in the root directory, configuration.php.
Opened the file up and started checking the entries and notice the “cache_file” referred to memcache which was the error message I got every time I closed out of a component.
Then I down loaded the file in case I needed to restore it. I changed memcache to the default of file. Saved the config file and that one small change fixed the backend issues as well as the links to all the forms on the frontend of the site.