A couple of users have hit issues like this:

No entry for terminal type "unknown";
using dumb terminal settings.

This seems to be coming out of PHP because TERM is not defined, but it's unclear exactly which circumstances cause this or where to stick TERM to make sure it is defined. Possible repro:

if it matters, [issue repros on] fresh CentOS 6.5, with php from CentOS repo, not epel or 3rd party.