Packager is used to replicate (or package up) an environment from a user on one computer for the benefit of another user on another computer — potentially from another company. In operation, the Packager gathers all files related to a particular master design file. These file are then analyzed and the Packager reproduces the same file system structure as the source, based on the category of the files. This environment includes:
line style settings
attached (and nested) references
Some times when extracting the files from the .pzip file there will be "0" number of entries. A reason for may be that the file size limitation has been met.
File size limit cannot exceed 4 GB(that applies to the compressed and uncompressed size of individual files and the size of the whole zip file). The maximum number of files allowed in a package 65,535.
You will be forced to reduce your file size or number of files before create the packaged file for extraction, i.e. raster files can be quite large so reducing the number of these files in the package or removing them completed might be helpful.