Constraintlayout错误Android Studio

Question

I was happily developing on Android (making some design) when I moved a button up in hierarchy and everything got weird. I'm using Constraintlayout for better alignment.

As you can see, on the blue screen there's no two buttons neither Guidelines. I tried to rebuild but some NonInfo Nullpointer appeared

Any suggestion? Do I have to re-do everything from scratch?

Info: I was editing it on Landscape before this happened

Answer 1

If you could post your XML, that would be helpful. Which version of ConstraintLayout are you using? Also, you should check out Android Studio 2.3, we made a ton of improvements in the layout editor.