Hi there,
Any body know what these 2 errors mean?

Failed to load resource: net::ERR_BLOCKED_BY_CLIENT http://www.googletagmanager.com/gtag...A-55808381-2:1

Failed to load resource: the server responded with a status of 404 (Not Found) /favicon.ico:1
I don't have a favicon on the site.

I am getting the same results on 3 of my sites - they are both in red, so pretty serious and I need to fix them?