Ah I see, thanks for clearing up the confusion!
Note this is not particular to the NodeBB rocket theme, but is also the case for any other themes that I've tried installing. The odd thing though, is that even though the theme throws an error during installation it is listed in the themes list in the administrative dashboard, however when you attempt to use it, most of the time you get a broken version of the theme, or more errors are thrown and NodeBB becomes unstable.
RE: Unable to install any NodeBB themes
Unable to install any NodeBB themes