Depending on the size and complexity of your website, some builder actions may take a little while to complete. You can still cancel these actions by pressing the "Cancel" button (once available).
When creating a backup file, the action can be canceled at any moment;
When trying to preview the website, the action can be canceled after 30 seconds;
When trying to publish the website, the action can be canceled after 60 seconds. You may need to confirm the cancellation if the website publish gets to the "Upload" stage.
If any website builder action gets stuck - it will be automatically timed out and can be retried after 5 minutes.