Fixing the Joomla! 3.4.0 extensions installer bug

After updating to Joomla! 3.4.0, you may have encountered some extensions that did install in previous Joomla! versions are now throwing the message:

What is causing the error

Joomla! 3.4.0 introduced a new security feature, scanning uploaded files for potential dangerous code. For example, it scans uploaded archives for PHP code - something that should not be done in the Extensions Installer (com_installer). Fortunately, Joomla! contributors already debugged and fixed this (pull request here) so if you don't want to wait until 3.4.1 is released, read this blog post.

Workarounds

• Using 'Install from Directory' - by unzipping the archive in a temporary path, pasting that path in the 'Install Directory' field and clicking on 'Install'.
• Using 'Install from URL' - although for commercial extensions this isn't viable since most of them will not have directly accessible URL for the archive. You can upload the archive on your website and point it in the 'Install URL' field (for example, upload 'com_my_extension.zip' in the root of your website and just type in http://www.your_website.com/com_my_extension.zip). Remember to delete it after you're done.
• Applying the fix manually. Read on below for instructions on how to do that.

Fixing it manually

Applying the fix manually can be done with minimum knowledge:

• Open your FTP account, connect to your website and go to the administrator/components/com_installer/models/ folder. FileZilla is a good FTP client if you're not familiar with them. Your hosting provider should provide you with a username and password to connect to your website's FTP.
• Create a backup of install.php (download it to your computer) just in case.
• Edit install.php (on your website) with a text editor. If you don't have one, I strongly suggest you check out Notepad++.
• Replace:

        $userfile = $input->files->get('install_package', null, 'array');
  

  With:

        $userfile = $input->files->get('install_package', null, 'raw');
  

  Scroll down the file to find:

        JFile::upload($tmp_src, $tmp_dest);
  

  And replace this one with:

        JFile::upload($tmp_src, $tmp_dest, false, true);
  

• Just save the file - if you're using FileZilla it will automatically prompt you to re-upload the modified file. If not, you'll need to upload it manually.

After the changes are done, try again to install the extension you were having trouble with - it should work properly. If not and another error message comes up (hurray!), we do have a guide to debug the installation of Joomla! extensions.

If you encounter issue on installing our joomla extensions or joomla templates please feel free to open a ticket to our support department.