MyBB Internal Error

MyBB has experienced an internal error and cannot continue.

Error Type:
(8192)
Error Message:
preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead
Location:
File: inc/class_parser.php
Line: 321
Code:
318.         $message str_replace('$''$'$message);
319.         
320.         
// Replace the rest
321.         $message preg_replace($this->mycode_cache['find'], $this->mycode_cache['replacement'], $message);
322. 
323.         
// Special code requiring special attention
324. 
Backtrace:
File Line Function
/inc/class_error.php 171 errorHandler->output_error
[PHP]   errorHandler->error
/inc/class_parser.php 321 preg_replace
/inc/class_parser.php 143 postParser->parse_mycode
/inc/plugins/shoutbox_ajax.php 380 postParser->parse_message
/inc/plugins/shoutbox_ajax.php 205 shoutbox_ajax_shouts
[PHP]   shoutbox_ajax_show
/inc/class_plugins.php 101 call_user_func_array
/inc/functions.php 83 pluginSystem->run_hooks
/inc/functions.php 671 output_page
/printthread.php 47 error