I've got an Animator which I can open and use fine in Unity 5.5. However, in Unity 5.6.0b9 (possibly earlier), when I select all but one of the transitions, I get the following error and, obviously, no transition view. Code (csharp): Difference in effective length between states is too big. Transition preview will be disabled I'm not sure sure what "effective length" this error message is referring to, but the length of the clips is between zero and about ~.5 seconds. I've also created a case, ID is 883536, where I've attached a small demo project.