I looked into the problem last week. Unfortunately, I don't have much of an answer yet. Error code 8 is "The mixer device did not process the message", which indicates that the mixer (the master volume controls) either isn't installed, or perhaps there is more than one 'device' installed.

I recall several years ago, another CSDS user had a similar problem. I believe he was also using a Thinkpad!

This is what he says:

I tracked the problem down to a Plug and Play C Audio Video card. The error message was annoying but didn't cause any functional problems. I ended up uninstalling the Drivers for the Card and the problem was resolved. Another work around was to leave the PCMCIA card installed. This also allowed me to load the program without any errors (But only on one configuration) Another option is to create a second configuration that does not have the audio card in it's configuration.

This error is really only just an annoyance. Since CSDS can't control the mixer, it simply greys-out the appropriate controls on the music player.

As of CSDS 1.15, there is a 'preference' that disables this error message from appearing. Goto 'System | Settings... | Music' and check the 'Disable error message 'Unable to Open Mixer' checkbox.