GetComponent Reference are lost after use Animator

Hi, I have this kind of "bug" happen to me since several versions ago(since 5.2 I think) Actually Im using 5.3.4 and still happening.

The problem is something like this:

I have regular scripts with reference like "GetComponent()" and the script work all good. No problem, no error, no warning. Everything is working perfect.

But if I use the Animator window to setup something, after that when I press play all reference are lost. I got null error like if the GetComponent is not working(In the Start/Awake/Update/Etc)

I cant fix this error, except closing Unity and re-opening. Then everything works fine again.

If I'm missing any important info let me know. This bug is kind annoying, I can still work on my project, but everytime I use the Animator I have to restart the program in order to keep working.

If someone know any solution plz tell me so I can fix it.

Sorry for my bad english, grettings!