I have the same problem creating a notebook, and also received an error when attempting to give Feedback. Following the Feedback link and after filling out the form it came back with:
Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /tools/feedback.
Reason: Error reading from remote server
Apache/2.2.21 (Linux/SUSE) Server at http://www.lds.org Port 80
I was able to create a Study Notebook from the Scriptures app on my Iphone. This app called it a Document. After creating it there, and syncing, I went back to the web page, and the notebook was there.
I’m not sure that was supposed to be the only way to do it. But it can be done that way for now.