I've updated Joomla to 3.6.2 in the past month on a site. I'm looking to update Akeeba Extensions but I don't have either the side menu or upload box in the Extensions: Install page. I have reinstalled core files from Components > Joomla! Update and also checked the database is up to date.
I was using Firefox on Mac and found an error in firebug about a local storage file being corrupt. (NS_ERROR_FILE_CORRUPTED) This seemed to prevent the form and menu from showing. Switching to Google Chrome resolved the issue for me.