"Error rewriting document" when creating binding

When trying to set a binding for the color property of the statusRect in the attached project, the error "Error rewriting document" is shown. See the attached video for the full reproduction.

There's also an error shown at startup, but it disappears too quickly to be possible to read.

The project was originally created with Design Studio 4.5.

Update: This also happens with a freshly created project in Design Studio 4.6, when following this Quick Start Guide: https://doc-snapshots.qt.io/qtformcus-dev/qtul-qsg-traveot2g-designui.html