DEV builds released after MechJeb2-2.14.3.0 are not compatible with PersistentRotation.
As soon as any vehicle is launched the logs fill up with spam [EXC .....
Player.log
KSP.log

PRs reflection will have to be updated after the dev branch is stable, this isn't a bug in MJ. Since principia and RO have their own PR-like mechanics and conflict with PR this isn't a priority.