Unity3D 模型导入Error

在导入3d max模型的时候报错：

3ds Max could not be found.
Make sure that 3ds Max is installed and the max file has 3ds Max as its 'Open with' application!

形成的缘由是由于我直接导入.max文件可是我电脑上面没有安装3Dmax.   unity须要导入.fbx才行。