Hello, I had your problem this morning and I didn't know what to do.
I figured out I was using the library @types/es6-shim to get some typings for Promises and other es6 stuff in other libraries of my own that I later imported to my project. When I imported these libraries I developed to my project I started getting the error.
Then I saw I had installed typescript as a dependency and I saw it uses the library lib.es2015.d.ts which conflicts with @types/es6-shim. I discovered this by building to android. When I did this I got a lot of errors in the console telling me there were duplicates in some typings.
The way I fixed it was removing @types/es6-shim from my node_modules folder and then removing the triple slash references from my modules (so they would use lib.es2015 and not @types/es6-shim.
I hope this helps