RPL7.X.X extra add-ons like Flex add-on need Zend Optimizer to run. So it’s mandatory that your server can support Zend optimizer .

Zend Optimizer™ is a free application that runs the files encoded by the Zend Guard, while enhancing the performance of PHP applications. (Only some of third party programs &  add-ons need this.)

You can check the php version of your server in Joomla through following path:

 -> Help->System Info

 &  -> Site->System Information

After you found the version of your server php, you must download the correct version of zendtest file from our servers and upload it to your server to see if Zend Optimizer is installed on your server:

zend5.2.php for php 5.2

zend5.3.php for php 5.3

You should then run the zend file by going to the url http://yoursite/zend(version).php and check the output.

Zend Optimizer should be installed by your server administrator. You need to contact your server administrator if the above mentioned files don't give a proper result.

If one of these two appear for you when you go to http://yoursite/zend(version).php, it shows that Zend Optimizer is installed on your site.