I'm using designer 1.0.0.0.54 (25.579.520 bytes).
Imported processes open ok, it's just that building the package that raises errors.
Btw, the "no interfaces found" error occurs also for a simple test process created by the designer.
About the package name: should it be "defaultPackage" (to have console visibility) or anything else ? I tried that name but I got even more errors as reported in my post.