/administrator/index.php?option=com_joomlaupdate I click
Install the update to update from
3.7.5, but immediately after clicking that button I receive a browser popup window
I am logged into Joomla okay with a
super user account, and the database user has full rights to the database.
After I click OK to the
invalid login message, I am taken to the update screen where nothing happens.
If I visit Extensions > Manage > Install, and try and upload
Joomla_3.5.1-Stable-Full_Package the screen will refresh and nothing happens.
If I unzip
Joomla_3.5.1-Stable-Full_Package into the site's directory, and refresh admin (after deleting the installation folder), I get a pile of errors at
Extensions > Manage > Database > Fix.