My Udongraph doesn't work with animator

Hello
I’m making some worlds. And there’s a very critical bug.

In my project, all of the Udon graph’s scripts that reference the animator reference Null values. This is strange. I dragged and dropped the exact object I needed in the Inspector window and it has the correct animator registered to it. However, when I run the script in play mode, the moment I refer to the animator’s parameter value as SetBool, it references a Null value and causes an error. At this time, if i change the bool parameter to true directly in the editor’s animator window, I can see the animation running.
And if I upload this to vrchat or test it with vrchat client through build & test, it works normally. The same problem occurred a few months ago, but I couldn’t solve it and had to create a new project.
It’s so sad that I have to create a new project every time this problem occurs. I want to solve this problem.