As @ww has pointed out it looks like you have other MX's in your network that are licenced as Enterprise feature only. You can't mix Advanced Security and Enterprise licences with your MX's. The Advanced MR licence wouldn't affect anything here.
We have had our licenced converted previously with Meraki Support from Enterprise to Advanced Security but it effectively cuts the licence time in half due to the upgrade.
Darren O'Connor | uccert.co.uk https://www.linkedin.com/in/darrenoconnor/
I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.