My Quick Fix

Problem

When trying to add a Plugin, Component or Module in Joomla’s Extension Manager, you might get the following error:

JFolder::create: Could not create directory
Warning! Failed to move file.

Shown here:

This is likely – but not definitely – to be after the site has been moved from location to another, a change of directory, or server.

Solution

When a Component, Plugin or Module is added, the Joomla system attempts to copy the installable zip to a temporary directory, called ‘tmp‘. From there, PHP extracts the files and installs them. The error above usually occurs for one or more of the following reasons (in order of likelihood):

The path to the ‘tmp’ directory is wrong in the Joomla configuration file

In the Joomla installation root, find the file called ‘configuration.php’. In this file there should be a line with that says something like:

var $tmp_path = ‘C:\\path\\to\\your\\cms\\tmp’;

A masked live example is shown here:

Check that this path is correct, and that the ‘tmp’ directory truly does sit in that location. In this example, the directory would need to be here: d:\clients\sites\[my client]\tmp.

The temporary exists, but is not ‘writable’

If the ‘tmp’ directory has the wrong permissions, the web service won’t be able to copy the installer files to it. To check/correct this you will need  access to the server physically, or via a remote admin method like RDP (terminal services), VNC or similar.

Find the ‘tmp’ directory in the web root, and view the permissions. The IIS Guest account, called ‘IUSR_[machinename]‘, needs to be given ‘modify’ privileges. Example shown below:

The temporary directory doesn’t exist

To check this, navigate to your web root (often wwwroot) and check that a directory called ‘tmp‘ exists. This directory should have been created when the Joomla was installed, but it’s conceivable that it might have been deleted… maybe? If it doesn’t exist, create it, and make sure its ‘writable’ (see previous step).

If none of this works, or you spot a mistake,  post a comment.