Support

There is no such thing in our code. A third party plugin changes the "layout" URL parameter to "landing". This is a non-standard behavior that constitutes a bug on the part of the third party plugin. I recommend trying to disable third party plugins –especially system plugins– one by one until you find the one that's causing this issue. My educated guess is that it's either code by a plugin written by your template's vendor or a plugin that comes with a SEO solution. In either case you need to contact the vendor of the plugin and let them know that they are doing something completely wrong that breaks the standard way Joomla! is expected to work, namely when a layout parameter is not present in the URL none should be added so that Joomla! can use the "default" layout.