How to set Language filter plugin in an higher priority ?
Since Joomla 3.6.1 you have to set the language filter in an higher priority.
1) you need to connect on the administrator Extensions > Plugins
2) Filter your plugin by type "system"
3) Order the filter by "Ordering Ascending"
4) Use the drag and drop system on the left to order the Plugin "Language filter" in the first position or before the Falang Database Driver.