It's url/admin.php
However, you may not be able to access that depending on the nature of the problem.
Enabling debug mode is likely the only option to get more details.
Thank you again, I enabled debug mode and my log has this error
Zend_Controller_Response_Exception: Cannot send headers; headers already sent in /home/enixor/public_html/forum/library/config.php, line 6 - library/Zend/Controller/Response/Abstract.php:321
Generated By: Unknown Account, A moment ago
Stack Trace
#0 /home/enixor/public_html/forum/library/Zend/Controller/Response/Abstract.php(115): Zend_Controller_Response_Abstract->canSendHeaders(true)
#1 /home/enixor/public_html/forum/library/XenForo/ViewRenderer/Abstract.php(63): Zend_Controller_Response_Abstract->setHeader('X-Frame-Options', 'SAMEORIGIN')
#2 /home/enixor/public_html/forum/library/XenForo/ViewRenderer/HtmlPublic.php(18): XenForo_ViewRenderer_Abstract->__construct(Object(XenForo_Dependencies_Public), Object(Zend_Controller_Response_Http), Object(Zend_Controller_Request_Http))
#3 /home/enixor/public_html/forum/library/XenForo/Dependencies/Public.php(207): XenForo_ViewRenderer_HtmlPublic->__construct(Object(XenForo_Dependencies_Public), Object(Zend_Controller_Response_Http), Object(Zend_Controller_Request_Http))
#4 /home/enixor/public_html/forum/library/XenForo/FrontController.php(547): XenForo_Dependencies_Public->getViewRenderer(Object(Zend_Controller_Response_Http), 'html', Object(Zend_Controller_Request_Http))
#5 /home/enixor/public_html/forum/library/XenForo/FrontController.php(141): XenForo_FrontController->_getViewRenderer('html')
#6 /home/enixor/public_html/forum/index.php(18): XenForo_FrontController->run()
#7 {main}
Request State
array(3) {
["url"] => string(73) "
http://www.enixorigin.com/forum/threads/colorless-infinity-spectrum.2220/"
["_GET"] => array(0) {
}
["_POST"] => array(0) {
}
}