Failed to determine free disk space for … error 75

This happens when the underlying data store cannot be queried for remaing qouta.

Explicitly set a quota for store or ignore. See quota error.

0x0 or disk write errors

The docker container does not have permissions to write updates to the data mount.

Explicitly set permissions for Conan Exiles files.
chown -R conan:conan /data/server/ConanSandbox

Wine Taking Long Time for First Start

winehq may potentially take ~5 minutes on first boot to launch, due to blocking on boot events:

0014:err:ole:get_local_server_stream Failed: 80004002

__wine_kernel_init boot event wait timed out

This is a suspected issue with the GCC build toolchain, but has not been resolved yet. See GCC breaks 64bit wine and wait timeout.

Steam container should pre mitigate this, however, system updates could change that. Letting the container run will resolve itself. See manual update for container specific resolution.