The issue may simply be that you haven’t hit the “Enable Google Maps” checkbox on the backend, under Events –> Settings. Once that is enabled you’ll have the option to embed Google maps in your frontend event listings and — if you’re a PRO user — to see a map preview on the backend while creating your new events. Remember that after enabling Google Maps on the backend, you’ll also need to set how it displays (i.e. embedded in the post; just a button to view at Google Maps; or both) within each event you create.
If your setting is correct and you are still experiencing a problem with Google Maps, the best thing to do is to add an API key under Events –> Settings –> APIs. Having a valid key entered there will help Google Maps communicate with The Events Calendar. This is a particularly important step for sites with high traffic, or if you use Google Maps in another feature or plugin.
If these steps do not resolve the issue, please post a thread to our help desk so we can troubleshoot further.