.band files not opening from previous version

I copied my .band files from another mac and cannot open them when copied to my imac running GB 11. Not sure of the version of the older GB software but but the O/S was Mac OSX10 and the previous version of GB. A GetInfo on the .band files says they are GB Projects on the new mac. But when I try to open with either GB 11 or Logic I get a "The file couldn't be opened" message. Any ideas?

Thanks