Troubleshooting Magento Activation Errors
Can not connect with shop: 404 Not Found

If you are getting this or a similar error (500 or 503 error) when trying to activate your Magento in the POS backend the first thing to do is checking whether your Magento API is working correctly.The URL that we are trying to reach is as follows:
http://YOUR_MAGENTO_DOMAIN/pos/index/index
Going to the link above should get you to a page where you should see the following error:
{"error":{"message":"API access denied: Invalid API key."}}If the link redirects to your HOME page or your store's 404 page then you probably have a redirection of some kind configured on your web server. Double check that and make sure the link above is showing the specified error.
On the other hand, if Magento is reporting an error, check that report to see whats going on.
getaddrinfo ENOTFOUND
Please check if the domain your store is using is publicly accessible, it seems our server is not being able to reach your store. It might also be a firewall configuration issue.
SSL UNABLE TO VERIFY LEAF SIGNATURE
There seems to be a problem with your server's SSL certificate configuration. Self-signed certificates will be rejected by our system. Make sure all intermediate certificates were added if any.
Don't hesitate to
 contact us if you need assistance.