After update to Joomla 3.1.4 or later, some 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
This is not resolved.
Change the source code from something similar to this:-
$browser = JBrowser::getInstance(); //...
To this (with legacy way to load classes):
JLoader::import('joomla.environment.browser') // Add this linecode $browser = JBrowser::getInstance(); //...