Gmail app stuck after receiving message "Try notifications for only your high priority emails".
A few weeks ago my Gmail app showed a message (in the Primary tab) saying "Try notifications for only your high priority emails". Without me doing anything the app then displayed the error message "Oops! An error occured. Latest changes may not have been saved". If I press OK the error message returns after just a second. I do not longer get any notifications, cannot access any emails on the Iphone or use the app at all. I haven't found any settings on my Iphone 5S that I can change. What to do? Grateful for any help.
iPhone 5s