Probably just a nuisance, I didn't see any serious problems:
[info] Loading external rule(s) built against an old version of Scalafix (0.9.31).
[info] This might not be a problem, but in case you run into unexpected behavior, you
[info] should try a more recent version of the rules(s) if available. If that does
[info] not help, request the rule(s) maintainer to build against Scalafix 0.10.1
[info] or later, and downgrade Scalafix to 0.9.x (x>=31) for the time being.
Probably just a nuisance, I didn't see any serious problems: