AceSEF does not work with JoomFish

Go to Extensions -> Plugins and check that the System - Jfrouter plugin is disabled.

If disabling this plugin causes the following error:
mod_jflanguageselection.php on line 75


Then apply the following steps:

OPEN
modules/mod_jflanguageselection/helper.php

FIND
$menu->_items = JFModuleHTML::getJFMenu($language->code, true);

REPLACE
// $menu->_items = JFModuleHTML::getJFMenu($language->code, true);