Unable to install on RPi Model B running Debian Stretch

I am trying to install on my old RPi Model B running Stretch. I get an error

./setup-seafile.sh: line 472: 8238 Illegal instruction LD_LIBRARY_PATH=$SEAFILE_LD_LIBRARY_PATH "${ccnet_init}" -F "${default_conf_dir}" -c "${default_ccnet_conf_dir}" --host "${ip_or_domain}"

I’m not sure if this is because the RPi Model B on ArmV6 is not supported yet. I do not see anything about this in the manual.

Any help is appreciated.

Yes, the HW is the issue, but check this thread. You can create your own seafile package using the build3.sh script.