Call to undefined function

Created by Boris Basara
Last updated: May 16, 2018

Problem

If you have a fatal error: Call to undefined function mb_internal_encoding() or similar this mean mbstring module is not installed on your server.

Solution

If it was installed, it would be displayed on your phpinfo page Admin → System → Settings → System →  PHP Info

You must explicitly enable the module on server configuration or contact your host to solve this.