Index error line 304

Hello
Any help please.
I have one error but don't understand the code to know what's wrong.

Code: [Select]

Line 304==> &raquo; '.$txt['you_have'].' <b>'.$user_info['posts'].'</b> '.$txt[21].'<br />
Thank you

from Simple Machines Community Forum http://ift.tt/29bMS5e
via IFTTT