I seem to have a major problem in the back-end of my site, but I am stumped as to where to fix it. When I try to update my site from J3.4.8 to 3.6.5 with the Joomla!Update component, the screen freezes at the "Updating your Joomla files."
I have tried to update the site directly by uploading the Joomla 3.6.5 package file from Extension Manager, but I get error "JInstaller: :Install: Can't find XML setup file." I have tried to install the update from the tmp directory, but I get the same error.
At this point, I can make no updates to my site. When I try to open an article, I get this error: "Fatal error: Call to a member function getTable() on boolean in E:\xampp\htdocs\ddauto\libraries\legacy\controller\form.php on line 366"
If I try to change a setting in Global Configuration, I get this error: "JForm::validateField() rule
Any help or insight would be greatly appreciated! I downloaded a backup of this site to my local xampp file to work on, but these are the same errors I was getting on my live site.