This message is spit out in stdout/stderr when there's an issue, but the message does not include the server reply. It would be great to include the server reply for troubleshooting issues. I am in many channels and I worry when I start NeoChat that it's flooding the homeserver with dozens of requests and I'm getting instantly rate-limited (HTTP 429).
I can reproduce this using the current Flatpak (24.08.3) on Fedora Linux 41 - the specific message for me was: > qrc:/qt/qml/org/kde/kirigamiaddons/labs/components/Avatar.qml:201:9: QML QQuickImage: Error transferring https://matrix-client.matrix.org/_matrix/client/v1/media/download//?timeout_ms=20000 - server replied: But the server reply is cut off as in your case.
Fix in libQuotient: https://github.com/quotient-im/libQuotient/pull/832