We're getting this message on one of our apps: "Your query touched some business assets which cannot be viewed in dev mode app. Please make sure all business assets the dev mode app is accessing are either with in the same business as the app, or under the caller if app doesn't have a business. Dev mode app and accessing asset are not owned by same business."And sounds like we're not the only ones:
https://stackoverflow.com/questions/56432347/facebook-marketing-api-asset-access-suddenly-denied