appInits[i] is not a function

polyfills.js:3 Unhandled Promise rejection: appInits[i] is not a function ; Zone: <root> ; Task: Promise.then ; Value: TypeError: appInits[i] is not a function
    at new ApplicationInitStatus (share.js:23)
    at AppModule__1Injector.createInternal (module.ngfactory.js [sm]:1)
    at AppModule__1Injector.NgModuleInjector.create (share.js:23)
    at NgModuleFactory.create (share.js:23)
    at share.js:23
    at t.invoke (polyfills.js:3)
    at Object.onInvoke (share.js:23)
    at t.invoke (polyfills.js:3)
    at n.run (polyfills.js:3)
    at NgZone.run (share.js:23)
    at PlatformRef_._bootstrapModuleFactoryWithZone (share.js:23)
    at share.js:23
    at t.invoke (polyfills.js:3)
    at n.run (polyfills.js:3)
    at polyfills.js:3 TypeError: appInits[i] is not a function
    at new ApplicationInitStatus (http://localhost:8100/build/main.js:4967:45)
    at AppModule__1Injector.createInternal (ng:///AppModule__1/module.ngfactory.js:503:36)
    at AppModule__1Injector.NgModuleInjector.create (http://localhost:8100/build/main.js:5596:76)
    at NgModuleFactory.create (http://localhost:8100/build/main.js:5569:18)
    at http://localhost:8100/build/main.js:6807:61
    at t.invoke (http://localhost:8100/build/polyfills.js:3:14529)
    at Object.onInvoke (http://localhost:8100/build/main.js:6184:37)
    at t.invoke (http://localhost:8100/build/polyfills.js:3:14469)
    at n.run (http://localhost:8100/build/polyfills.js:3:9741)
    at NgZone.run (http://localhost:8100/build/main.js:6053:62)
    at PlatformRef_._bootstrapModuleFactoryWithZone (http://localhost:8100/build/main.js:6805:23)
    at http://localhost:8100/build/main.js:6847:59
    at t.invoke (http://localhost:8100/build/polyfills.js:3:14529)
    at n.run (http://localhost:8100/build/polyfills.js:3:9741)
    at http://localhost:8100/build/polyfills.js:3:6774

Argh!! Help!

Turns out I had problems in app.module.ts. Had Lambda instead of Function.

export function bla

then use bla in

providers: useFactory: bla