Zend certified PHP/Magento developer

Why are my Wikimedia pages are showing a LUA error?

I downloaded and installed media wiki and imported some xml files from wikipedia’s special:export.

I enabled scribunto and parserfunctions and enabled all other necessary extensions.

But all the pages are showing alot of this error:

:Lua error: Cannot create process: proc_open(/dev/null): Failed to open stream: Operation not permitted

I chmod 777 the lua file and all contents of the directory /extensions/Scribunto/ as well as 777 to /dev/null in vain.