It is a common php error appears when PHP handler unable to detect the server temporary folder automatically. A solution to the problem is to define the upload_tmp_dir of the php explicitly. You can do that by editing the php.ini file. Here is an example on how to do it:
To find the running php.ini file, use phpinfo:
root@chicago1 [~]# php -r ‘phpinfo();’|grep php.ini
Configuration File (php.ini) Path => /opt/cpanel/ea-php56/root/etc
Loaded Configuration File => /opt/cpanel/ea-php56/root/etc/php.ini
As the command suggests, your php.ini file is located under the following:
Now, edit the file using your favorite editor:
Find the location of upload_tmp_dir, which is usually commented out like the following:
Uncomment it by removing the semicolon from front and define the temporary directory location:
upload_tmp_dir = /tmp
Restart your apache.
There is another way you can do it. To do this, go to WHM >> MultiPHP INI Editor >> Editor Mode >> Find upload_tmp_dir and edit it accordingly.
This would create a user.ini file to be included with the original php.ini file.
If none of the above solution works for you, you are probably seeing the error from modsecurity, try following the following steps to see if that overcomes the error: