Hi larsenteam,
I’m sorry to hear you are hitting difficulties. Here’s the problem:
Warning: you have included the Google Maps API multiple times on this page. This may cause unexpected errors.
So your theme or another plugin is also trying to use the Google Maps API at the same time as The Events Calendar/Events Calendar PRO and that can indeed cause problems.
With that in mind the next step is to figure out what is conflicting. Can you try deactivating all other plugins and switching to a default unmodified theme like Twenty Twelve? At that point, confirm this is no longer a problem then begin reactivating everything. Test at each stage to see if you can determine where the conflict lies.
Let us know how you get on 🙂