.logicdatafiles saved in Logic 1.x are not compatible with Logic 2.x. The Logic 2.x software uses a new
.salfile format. Several users have expressed their need for
.logicdatacompatibility in Logic 2.x in an idea post here. Feel free to add your votes/comments to it!
.logicdatafiles are forward compatible within Logic 1.x. That means that files saved with older versions of the Logic 1.x software can be opened by newer versions of the Logic 1.x software. However, backward compatibility is not supported. You cannot open newer files with other versions of the software.