I have created the canvas app , today I want to edit it in the app builder but I can't do anything in my app is showed the error as the pictuer below. Anyone can help me to clarify this problem? thank you in advance.

I have created the canvas app , today I want to edit it in the app builder but I can't do anything in my app is showed the error as the pictuer below. Anyone can help me to clarify this problem? thank you in advance.