Missing JBrowser class after upgrading
From Joomla! Documentation
After update to Joomla 3.1.4 or later, some extensions that depend on the native autoloader, with a working code before, may stop working.
Fatal error: Class 'JBrowser' not found in path/to/file.php on line XY
This issue only affects some 3rd party extensions in Joomla! versions 3.1.4 and higher
What is the cause
An instance of Joomla! Core using JBrowser has been removed causing it not to be automatically loaded on all pages.
How to fix
Change the source code to something similar as below.
$browser = JBrowser::getInstance(); //...
To this (with legacy way to load classes):
JLoader::import('joomla.environment.browser') // Add this linecode $browser = JBrowser::getInstance(); //...