The IBM Watson API service URL has changed. We have updated our code and released version 1.30.0 on 5/7. Unfortunately right after we submitted the new version, they changed the URL again. We cannot release version 1.30.1 until 1.30.0 has been approved by the Chrome Web Store, which can take up to 7 days. In other words, it may take up to 2 weeks for version 1.30.1 to arrive with the fix for IBM voices. If you were using IBM Watson voices, please select some other voices for the time being.
Edit: if you use Firefox, Read Aloud version 1.30.2 has working IBM Watson voices.