Comment 4 for bug 869685

Try this:

ar t /home/rogerb/Downloads/google-musicmanager-beta_current_amd64.deb

Is the data.tar inside lzma compressed? If yes then this is a dupe of 868188.

You can work around it in one of three ways

1. Installing with dpkg
2. Installing either the lzma or xz-lzma packages as they provide /usr/bin/lmza
3. setting up your own symlink such that /usr/bin/lmza points to /usr/bin/xz

Remember to mark this as a duplicate if it is your issue.