Meteor Devtools: Uncaught ReferenceError: Tracker is not defined

Just started developing a Meteor / React app. The app works as expected but DevTools causes an “Uncaught ReferenceError: Tracker is not defined” message in the console. DevTools will display DDP data but not Blaze or MiniMongo data. If I open the app in a new window without Meteor DevTools I do not get the error. Any idea what’s going on? Right now I’m only interacting with User Accounts.

I have this problem too. It looks like the extension uses Tracker variable from Meteor app.
To works with minimongo I have to use another extension:

Thanks uninstalling Meteor Devtools solved the same issue I had.

Thanks. Had the same problem. Uninstalling really helped.