A bug can occur in Joomla when Google recaptcha is being loaded in multiple places on a site. The error message "Empty Solution Not Allowed,” most commonly occurs when trying to edit content through frontend editing. The error shows after hitting the SAVE button. The easiest solution is to simply disable the recaptcha feature from frontend editing.

Recently had a shopping cart we manage show gibberish looking code only on mobile.  This is obviously not reassuring to customers and does bring up the concern of a possible hack. 

The problem was harder to troubleshoot because the behavior wouldn't replicate on a browser emulator which made it harder to find the error.  However, to save someone else the time, the problem was that the output compression level in the store setting needs to be changed to 0.

Many security tools and blogs suggest setting the open_basedir in the php.ini file.  The open_basedir directive "Limits the files that can be accessed by PHP to the specified directory-tree, including the file itself. ... When the file is outside the specified directory-tree, PHP will refuse to access it." *

However, it can often trigger the error:

JFolder::create: Path not in open_basedir paths

In order to solve this, you have three options: