If BlueStacks Air gets stuck on the loading screen after launch, this would be due to an older version of BlueStacks Air on your Mac or your installation getting corrupted.
What can I do to resolve this?
To resolve this:
Take a look at the steps below for a detailed walkthrough:
Uninstall BlueStacks Air by clicking on "BlueStacks", next to the 
icon, within the top bar ➔ Select "Uninstall BlueStacks" ➔ Go to the official website ➔ Download and install the latest version.
Once done, you will be able to launch BlueStacks Air without any issues.
Thank you for choosing BlueStacks Air. We hope you enjoy using it. Happy Gaming!