AngularFire2 - Cannot Find Module @firebase/database
Answer : I think it has to do with an issue with npm. When using yarn to install the modules, everything works flawlessly. yarn add angularfire2 firebase tldr: Node: 8.4.0/npm: 5.2.0 has issues, yarn works You could try with: $ rm -rf node_modules/ $ npm install $ npm install angularfire2@latest --save or to change AngularFireDatabaseModule by AngularFireDatabase . I had no luck trying to reproduce your issue. I would suggest if this is still an issue for you trying the following: Check for differences between my configuration below and yours View the notes for configuring ionic3 here Reinstalling npm (sounds crazy but occasionally I do this and issues disappear and I see mine is a little newer than yours) npm configuration $npm ls -g --depth=0 /Users/pbrack/.nvm/versions/node/v8.5.0/lib ├── cordova@7.1.0 ├── cordova-check-plugins@3.0.1 ├── ionic@3.13.2 ├── ios-deploy@1.9.2 └── npm@5.4.2 Configuration Steps $ ionic start angularfire2test blank $ npm instal...