The MyLibrary! app is currently experiencing an error for iPhones. If you are affected, you would see an error message after launching the app, and if you click "My Account", you would see a 2nd error message.
To resolve the issue, click the Menu button in the upper right corner of the app (this is the image of 3 horizontal lines), then click Sign Out. Close the app, then re-launch the app and click the Menu button in the upper right corner. Click Sign In.
Signing out and back into your MyLibrary! app resolves the error.