Good evening Andrew and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
We are sorry to hear about these error messages.
I would love to help you with this topic.
As a first troubleshooting step, could you please provide us with your complete system information in a private reply using the instructions found in the following link?
https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Based on what you are telling me, it sounds like your local install might not have full internet access.
Another thing to keep in mind is that you will need a completely separate API for your local install.
Finally, perhaps my colleague Nico’s post on a similar issue could be useful to you: https://theeventscalendar.com/support/forums/topic/authenticating-eventbrite-with-localhost-environment/#post-975194
Let me know if that helps.
Have a great day!
Geoff B.