Animation and Rigging Tools: FAQ, Known Issues and Feature Roadmap

Likely you have a userSetup.py both in your maya/scripts directory and in your maya/mayaVersion/scripts directory, so the two are fighting each other. Try deleting the one in your global scripts directory (documents/username/maya/scripts [on windows])

Also, worth noting, the scripts that ship with 4.12 are unfortunately not latest. It seems they pulled from a version months ago. If you want to get latest, please grab them from dropbox! (These are updated anytime anything is fixed or added!)

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