Avid 2018.12.1. Continuum 2019. Mac OSX High Sierra. After adding Pan and Zoom to a clip, if I turn on Motion Blur it results in a BFX Error 25. Turning off Motion Blur clears the error
That was a bug introduced in 12.0.0 as part of an optimization. We already have a fix for it internally and it will be a part of the 12.0.1 update that will be released soon.
Sorry for the inconvenience!