J3.x:Known issues with the new URL Routing parameter
From Joomla! Documentation
In Joomla! 3.7.0 there's the parameter to activate the new URL Router (Modern Routing).
To activate it for contents (but it is available also in contact and News Feeds) you need to access the Options of Article Manager, in the TAB Integration, and enable the "URL Routing" parameter. There are, however, currently known problems with this parameter activated
Errors reported
- No new URL Routing in Joomla 3.7
Versions affected
General Information
This pertains only to Joomla! version(s): 3.7.0
What is the cause
How to fix