Linkstation 500GL on Mac OS 10

[prjctfish]

I have a Linkstation that I was able to use on my Mac before El Capitan ( 10.11.6) and now when I try to log into the LS via Apple server  (Go To) I get an incompatible error. If I put the IP address into browser I get the Buffalo (blue Screens) user admin/config tool, but no way to get to data files. I don't see any web access settings which this post claims should be avaiable (http://buffalonas.com/manual/en/webac_nas.html#c).

I just want to grab some files before I archive the unit or be able to upgrade the firmware and continue to use the unit. Give how easily I can access the config tool I assume it worth it.

Thanks in advance for any help

Simon