This has been confirmed as a bug in the current version. An updated dll (VisBuildExt.dll) is attached to this post that rectifies this particular error.
Installation instructions:
1) download the updated VisBuildExt.dll file (available zipped @
ftp://ftp.kinook.com/VisBuildExt.zip)
2) backup the VisBuildExt.dll file in your Visual Build Professional installation path
3) overwrite it with the updated VisBuildExt.dll file
Note: this is an interim fix, and will be included in the next minor release of Visual Build Professional. The attached, updated file only fixes this specific issue and has not been fully regression tested, only update this file if you are encountering the "Zip file structure invalid" error as reported in this forum thread.