For a stable connection to Goodreads in All My Books, you need a personal API key. It is effortless to get it, here is the simple how-to.
First of all, you need a personal Goodreads account. If you still don't have it, register here. Do not forget to confirm your e-mail address by clicking on the link in your Inbox.
Now, when you are logged in to your Goodreads account, open this link and fill-in "Application name" and "Company name" fields with some generic values and check "I agree..." box, then click "Apply for a Developer Key" button.
That's all. You don't have to wait for any approval. Copy "key" value (you don't need a Secret key, only the shorter one).
If All My Books asks you for a key, you can paste it to the dialog and press OK key. Alternatively, you can add a key manually by following these steps:
Now, enjoy All My Books and Goodreads together :)