[Lynne]

Line 1881 of functions_newpost.php is:

PHP Code:

($hook = vBulletinHook::fetch_hook('private_newpm_reply')) ? eval($hook) : false; 


So,your error is being caused by a modification using the private_newpm_reply hook location. If you know which modification it is, just turn it off. Or, turn off the modifications one-by-one until you find the culprit. Then, go find the modification thread and see if a fix has been posted for this issue.