Here's an overview of the most common causes customers may experience when creating new or updated builds of their app(s).
I get an error message 'Communication with Apple failed'
In March 2021 Apple introduced a requirement to use two-factor authentication for logging in to App Store Connect.
If you get the error above, most likely you haven't configured two-factor authentication for your account yet.
Check your Xcode version
In many cases, the problem is caused by not having the latest version of Xcode installed or because some components are missing.
Solution: Make sure to install the latest version of Xcode and launch Xcode just after the update, in order to download (and activate) the required components.
Verify that you are logged in correctly
Make sure that in the Twixl app, you are logged in to your account on the Twixl platform.
Make sure Xcode is set up correctly, as specified in this article.