After upgrading to RC4, some of my pages didn’t render after async operations.
I can’t show my code here since there are nested functions.
But basically I use Observable to retrieve ajax and then show it on the page.
I can see the code is all executed and console.log shows the updated variables, but the page didn’t re-render.
Any ideas? Or is there a way to force it re-render?
Good luck getting help then. 
You can try to use NgZone to renter Angular zone.
I don’t know if this is the best solution, but I had to use it once in an app I’m building (changing values from variabled inside a setimeout were not reflecting in the view).
It happened after using angular 2.2.1 but not 2.1.1.
So I think it’s not about the code as it’s been working properly since rc0.
BTW, ionic serve is working perfectly.
But when I download it to my android device, it didn’t render properly.
From the sound of things, your code might just need to be updated.
Without seeing any code though, we cant give any more detailed information.
@mhartington I found the fix and it seems to be related to another problem I posted before.
In short, I use NgZone.run to do setRoot()
It fixes both problems of incorrect rendering and double tab page.