Surprise NaN generation in latest Threejs

Questions
1

So I am basically confused. My game uses Threejs and Yuka AI for much of its contents. I use Code as my editor and debug in chrome. Using the most current Threejs, I updated recently, I am generating NaN from simple operators usage in three.core.js. Commands like these in AnimationMixer generate NaN values

three.core.js at line 34607.
deltaTime *= this.timeScale; <=====produces NaN

	const actions = this._actions,
		nActions = this._nActiveActions,

		time = this.time += deltaTime,  <=====produces NaN