This morning I get this error message. How do I fix it?
Fatal error : Uncaught Error: Call to undefined function mb_internal_encoding() in /home4/mydomain/public_html/mydomain.com/tt-rss/include/functions.php:19 Stack trace: #0 /home4/mydomain/public_html/mydomain.com/tt-rss/include/autoload.php(2): require_once() #1 /home4/mydomain/public_html/mydomain.com/tt-rss/index.php(31): require_once(’/home4/mydomain…’) #2 {main} thrown in /home4/mydomain/public_html/mydomain.com/tt-rss/include/functions.php on line 19