Error message: Response is not a valid JSON response

Good morning, I need your help! I have my wordpress and woocommerce website hosted on azure, and when trying to edit a widget I get this error 'invalid JSON...' help!

I already read all the forums with the different solutions, and nothing works. I already installed the classic editor, save the permalinks, it still doesn't work, it only happens with the widgets, and I only have a problem in azure, because I had it in another hosting and it worked perfectly. :/