Hey folks, I wrote myself a code to get special Avatars for my users. I wrote it into the Core.php to test it and it worked fine. Now i wanted to make it to a proper Add-On because editing original files ist pretty stupid in my opinion. My Add-On is listening the "Init_dependencies" event and on call of the callBack is executing the following code: PHP: XenForo_Template_Helper_Core::$helperCallbacks['avatar'] = array('McAvatar_Listener', 'helperAvatarUrl'); to redirect the call of the "helperAvatarUrl" method to my own Add-On. If i now mount my Add-On the following happens: The Template seems to not be loading at all which can be seen in the following screenshot. http://i.imgur.com/rvUq6x1.png I hope you know how to fix this problem, in case you need the full source code feel free to message me. Suggestions on how to work around changing those variables or alternative ways are also appreciated.