To switch off the PHP safe mode please follow the following steps:-
1) Login to Plesk control panel.

2) Click on "Domains".

3) Select the "domain" on which you want to install the application.

4) Click on "Web Hosting Settings".

3) Switch the safe mode off by clearing the PHP 'safe_mode' on check box in the hosting account.
Make sure you click on "OK" once you have disable the php safemode check box.
