unity5.4 and NGUI3.9.9 when call Screen.SetResolution game window black

[noob22]

Hi!
As it said in title, we build for standalone exe and have a requirement which can change window size by button.
So we use api Screen.SetResolution , it work fine in untiy 5.3.5 or before.
Recently we update to unity 5.4.0 , everything work fine but this api.
It seems  UI dont refresh in time , our game window become black, like no cameras rendering.
We try reactive UI root then it appear again.
Any suggestions?

[ArenMook]

I can't say I've ever heard of this one... Can you first update to NGUI's latest 3.10.0, and if it still happens, submit a repro case for me to look at? support [at] tasharen.com

[noob22]

I can't say I've ever heard of this one... Can you first update to NGUI's latest 3.10.0, and if it still happens, submit a repro case for me to look at? support [at] tasharen.com

Thx for reply.
I have resolved this problem and there is nothing about NGUI.
Unity5.4 change graphics API for Windows to only Direct3D9 for default.
When I select auto graphics API, the problem is resolved.