Missing Installer Tabs
From Joomla! Documentation
Joomla!
3.6.0
Errors reported[edit]
After upgrading to Joomla 3.6.0, under certain circumstances, your installer tabs are missing (Install from file, Install from web, Install from folder etc..)
Versions affected[edit]
General Information
This pertains only to Joomla! version(s): 3.6.0
What is the cause[edit]
How to fix[edit]
CLEAR your cache, Clear your admin cache, Discover for new extensions, install the new plugins, enable the new plugins
See also: https://github.com/joomla/joomla-cms/issues/11098#issuecomment-232341213