I installed the gmap module thought I had everything configured properly but kept getting this error...
I finally realized that I was using a 'Google Maps API Server Key' when I needed to be using a 'Google Maps API Browser Key'! Perhaps some of the Google Map API Key instructions could be updated on the gmap homepage and README file. How about this...
In order to use 7.x-1.x and earlier versions of this module, you need a (free) Google Maps API Browser key. Here is how to get one:
1. Login at https://code.google.com/apis/console
2. Create project
3. Go to 'Services' and turn on 'Google Maps API v2'
4. Go to 'API Access' and 'Create New Browser Key' specifying your domain url(s)
5. Paste the Google API Browser Key here ./admin/settings/gmap
Hope that helps someone.