XF 1.1 When posting url links, this error shows

[onionaut]

preg_match() [function.preg-match]: Delimiter must not be alphanumeric or backslash
 
    XenForo_Application::handlePhpError()
    preg_match() in XenForo/Helper/Media.php at line 58
    XenForo_Helper_Media->_convertMediaLinkToEmbedHtml() in XenForo/Helper/Media.php at line 39
    XenForo_Helper_Media::convertMediaLinkToEmbedHtml() in XenForo/BbCode/Formatter/BbCode/AutoLink.php at line 174
    XenForo_BbCode_Formatter_BbCode_AutoLink->_autoLinkUrl() in XenForo/BbCode/Formatter/BbCode/AutoLink.php at line 156
    XenForo_BbCode_Formatter_BbCode_AutoLink->_autoLinkUrlCallback()
    preg_replace_callback() in XenForo/BbCode/Formatter/BbCode/AutoLink.php at line 131
    XenForo_BbCode_Formatter_BbCode_AutoLink->filterString() in XenForo/BbCode/Formatter/Base.php at line 488
    XenForo_BbCode_Formatter_Base->renderString() in XenForo/BbCode/Formatter/Base.php at line 467
    XenForo_BbCode_Formatter_Base->renderTreeElement() in XenForo/BbCode/Formatter/Base.php at line 444
    XenForo_BbCode_Formatter_Base->renderSubTree() in XenForo/BbCode/Formatter/Base.php at line 424
    XenForo_BbCode_Formatter_Base->renderTree() in XenForo/BbCode/Formatter/BbCode/AutoLink.php at line 53
    XenForo_BbCode_Formatter_BbCode_AutoLink->renderTree() in XenForo/BbCode/Parser.php at line 503
    XenForo_BbCode_Parser->render() in XenForo/Helper/String.php at line 218
    XenForo_Helper_String::autoLinkBbCode() in XenForo/ControllerPublic/Forum.php at line 540
    XenForo_ControllerPublic_Forum->actionCreateThreadPreview() in XenForo/FrontController.php at line 310
    XenForo_FrontController->dispatch() in XenForo/FrontController.php at line 132
    XenForo_FrontController->run() in /home/amulet1/public_html/index.php at line 13

When post url links, it shows this

Anyone encountered this before?

How can one resolve this issue?

Thanks!

 

[onionaut]

ah, found out it is due to a change i made in the facebook video embed code.