Category Archives: Firebase

AngularFire2 Cannot read property ‘indexOf’ of undefined

If you are using AngularFire in your project and you are getting the error:

Cannot read property ‘indexOf’ of undefined

you may have run into the same problem I did.  I previously had Firebase installed in my project as well as AngularFire.  The new version of AngularFire (AF2) already has the Firebase module pre-installed.  So to get your project compiling you will have to remove the standalone install of Firebase.  See more here.




I’m a mobile applications developer based in the UK, concentrating primarily on hybrid application development with Ionic but also with native development skills. Please visit for more information about me and how I may be able to help you with mobile application development, particularly with Ionic but also with other mobile frameworks and technologies.  Thanks for visiting.