I will email you a link to download the files. I've narrowed them down some, but they are still > 1 GB in size. I will also trim the script as much as possible.

In summary, what I've found is that with a certain set of source files, if there are 2 (or more?) install commands (non-overlapping), if the first install command is skipped ("If" condition not met), the second install command fails with Decompression Error #99.