Phaze, yea, it's weird that not everyone is effected. That person I replied to a few posts up obviously installed it fine as well. Both of you did clean installations so maybe it's something that's changed but only effects updates?
I'm really shooting in the dark here so I could be completely wrong. For now I modified the plg file to force it to install the previous version but unfortunately I am the developer of the MB Chrome extension and people reported there is an issue with the new version of the server and my plugin that needs to be looked at and I can't even develop at the moment (not to mention the new version of the server fixes the live tv for unRAID/Linux with some additional roundabout stuff).
I think that a lot of the stuff that was fluid before has now been standardized. When you started the plugin I think this was really the first real *nix package. Now there is unRAID, FreeNAS, and a few others so I am sure he isn't making changes to how the packages are built anymore.
If you can get some free time I would appreciate if you can work with Luke to get the unRAID MB plugin working again. I'll also be available to test any scripts you want.