few times when I tried to establish integration between Dynamics NAV 2017 and Office 365 for data migration through Edit in excel add-on I forgot to grant permission to Excel azure app. So for you to remember how to do that and which error you will get I will write a short blog post about that.
First, when you open Excel and enter server information you will get the message from the picture below.
And this really angered me because I know that my setup is perfect and why this does not work. And then I found the solution for that you must grant permission to that app to your account.
I hope this will help also to you to faster your implementation and for sure I know that now I will not forget to grant permission for my user.