In many cases, your web application might not work as expected due to certain enabled/disabled php_functions,
Using cPanel
Login to cPanel → Navigate to Software → MultiPHP INI Editor.
Navigate to Editor Mode → Select the Domain Name (Location).
Enter the PHP functions in front of “disable_functions = # # # #” to disable the PHP function → Click on Save.
Example:
disable_functions = exec, system, passthru, pcntl_exec, popen, proc_open, shell_exec
To enable the disabled function, remove the specific PHP function from the disable_functions list.
that's all