"Create readaloud" fails on the 3.0.0-alpha web image

Running the web-v3.0.0-alpha.32 image. I add an ebook and an audiobook, merge them, click "Create readaloud", and it errors out. I moved to the v3 alpha because I was hitting bugs on the 2.x branch.

Resolution: The 3.0.0 alpha images are not meant for public use — they are published for internal testing and readaloud creation is among the things known to be broken there. Move back to the latest 2.x release (downgrading to 2.14.10 restores working readaloud creation). The important caveat: upgrading to a v3 alpha runs forward database migrations that are not reversible, so a database that has been through an alpha may be left in a bad state even after you downgrade — back up /data before touching any alpha tag, and restore that backup rather than downgrading in place if you have one. Pin an explicit 2.x tag rather than tracking a floating tag if you want to be sure you never land on a prerelease.