Currently Being ModeratedOct 26, 2013 9:58 AM (in response to JUDY STADT)
when you installed GarageBand 10.0 the installer should have moved your GarageBand 6.0.5 to a subfolder in Applications. This version should still be working. If you are working on a tight schedule, use that GarageBand 6.0.5 version for the time being, to get your show done.
GargaeBand 10.0 seems to have a bug causing crashes, i.e. on 2007 models (iMac, MBP) and mid 2011 models. If you have one of these models, use GB '11, until there is a bug fix.
If you are using older drivers for Audio interfaces or are using plug-ins for custom instruments and sound effects, check with manufacturer's for compatibility with GarageBand 10.0 and Mavericks.
Currently Being ModeratedOct 26, 2013 12:19 PM (in response to JUDY STADT)
Your Midi One audio interface probably needs a driver. You must have some software installed when you originally set it up. Did you install a plug-in? I suspect that you need an update for the driver you are using with your interface cable. Some plug-ins are no longer supported.