error: Unable to allocate instance id

[justusranvier]

Shortly before Christmas I lost the ability to start Signal entirely, due to what appears to be some kind of incompatibility with org.freedesktop.Platform:

$ flatpak run --verbose org.signal.Signal
F: No installations directory in /etc/flatpak/installations.d. Skipping
F: Opening system flatpak installation at path /var/lib/flatpak
F: Opening user flatpak installation at path /home/signal/.local/share/flatpak
F: Opening user flatpak installation at path /home/signal/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: Opening user flatpak installation at path /home/signal/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: /var/lib/flatpak/runtime/org.freedesktop.Platform/x86_64/23.08/3c58ded6fa422d45d30b070f26e428617f6e6509d18cfa1c31f959494511da66/files/lib32 does not exist
error: Unable to allocate instance id