Fixing: ERROR in node_modules/@ngrx/store/src/store_module.ts(23,66): error TS1183: An implementation cannot be declared in ambient contexts.

gistfile1.txt

More on this here: 
https://stackoverflow.com/questions/37448491/angular-2-typescript-an-implementation-cannot-be-declared-in-ambient-contexts

And here: 
https://basarat.gitbooks.io/typescript/content/docs/types/ambient/d.ts.html

What worked for me: 
1) Find: ode_modules/@ngrx/store/src/store_module.ts
2) Removed '.d' from store_module.d.ts -> when I did this the project didn't compile :P
2) Then I added the '.d' again and everything worked :)
Still don't understand what happened :P

When the previous method failed I removed the 'node_modules' folder an run 'npm install' in the console :) everything is ok for now...