http://www.cnblogs.com/lopezycj/archive/2012/05/16/unity3d_tuchao.html
https://forum.unity3d.com/threads/time-range-447406-for-translation-curve-s-on-node-bone001-on-take-take-001-what-the.311408/
zoom out the 3dmax animation curve editor window,you will find a key frame at the far far negtive, or far far positive. Then delete it
