Hello! Well, I don’t know what to say, see it by yourself:
I’m absolutely sure that I do not have any error in my story, yet today appeared this warning when I first saved it. I tried closing my browser, update it, and log off and log in, but it keeps appearing.
Help? 
Maybe try to delete the scene you coded before this appeared, save it, paste it onto the script and save it again? It could be a bug
Yeah, I tried that, didn’t work. However, I did delete it log off and log in again and the error disappeared.
Mysteries…
Thanks anyway!
You’re welcome 