Problem with postnote and k2

Hi friend i've donwload postnote, it's very cool, and installed it by quickstart package, but i have a problem.
The site is ok, can you see in www.scetticamente.it/cms , but if i try to create or modify or see a content of k2 joomla write this error::: Fatal error: Call to undefined function mb_internal_encoding() in /home/hosting/scetticamente.it/www/cms/administrator/components/com_k2/tables/k2item.php on line 74

Someone can help me?
Thanks and sorry if my english is'nt good

It means that you haven't installed support for multibyte strings on your hosting - K2 uses it and it is necessary to correctly work. For me it is a bug in K2 because Joomla has a class JString which supports multibyte strings even on hostings which havent support for mb_ functions.

Thanks, i opened a ticket support to my hosting service.

dziudek wrote:

It means that you haven't installed support for multibyte strings on your hosting - K2 uses it and it is necessary to correctly work. For me it is a bug in K2 because Joomla has a class JString which supports multibyte strings even on hostings which havent support for mb_ functions.

Thanks was this the problem, now my hosting have enable mb and K2 work correctly.
Thanks