Comment 3 for bug 1468849

Since you removed the machine placement you've left in the -to flags so it's going to error as the bundle is no longer valid. You have placement directives, but no machines to place them on.

This describes the bundle transition that took place and has notes on the machine specification.
https://github.com/juju/charmstore/blob/v4/docs/bundles.md

Please let me know if I'm misunderstanding the problem or if this does not help.