When I add android.support.v7.widget.Toolbar
or another android.support.v7.widget.*
there are rendering problems.
But Support Library is up to date. And I complied in dependecies properly. I can import them in MainActivity.java
What is the problem?
UPDATE: Apparently they have fixed this bug in the final Android Studio 1.3 release (according to users reporting this issue solved in the issue tracker: https://issuetracker.google.com/issues/37043358).
This is a known bug since Android Studio build 1.1, which still exists in AS versions 1.2 and 1.3 beta. Switching the preview's API level from 22 to 21 fixes the for most people. While waiting for a fix you could try it as well.
UPDATE: This is already reported as a known issue of Android Studio (http://tools.android.com/knownissues#TOC-Can-t-Render-Layouts-in-Android-Studio-1.2)