Error: "Fatal error: ini_set/set_include_path does not work."

[MalastiC]

Good morning. I installed RoundCube following this tutorial: http://www.roundcubeforum.net/3-news-announcements/12-general-discussion/5034-how-install-roundcube-plesk.html

Everything went well, but when I try to enter I get this error:
Fatal error: ini_set / set_include_path does not work.

I do not speak English (I am translating with Google) and I find it very difficult to solve this problem.

Does anyone can tell me exactly what I do?

Regards,

[MalastiC]

It is working.

[blacksheep]

It is working.

how did you deal?