Using the 3D Rotation tool, I edited a rotation I previously made and now I get this output error:

TypeError: Error #1009: Cannot access a property or method of a null object reference.
at fl.motion::AnimatorUniversal/initTransformPointInternal()
at fl.motion::AnimatorUniversal/setTimeClassic()
at fl.motion::AnimatorBase/set time()
at fl.motion::AnimatorBase/end()
at fl.motion::AnimatorBase/handleLastFrame()
at fl.motion::AnimatorBase$/processCurrentFrame()
at fl.motion::AnimatorBase/handleEnterFrame()

I have searched for hours now and can't seem to find a solution. I sense it is still searching for the previous motion. Any idea on how I fix this? If so, can you break it down to someone who is not overly familiar with Actionscript and editing actions? Thank you so much in advance.