In my case I downloaded version 22 of Android M and Android 5.1.1 using Android Studio 1.2.1.1 but when I try to do a Hello World this same error showed me

So the solution for me was doing right click in app like the image below and choose "Open Module Settings"

then there you have 2 options. I've changed both with the last version I had.

Compile SDK version to API 21 Lollipop

and Build Tools Version to 21.1.2

Finally clean the project and Build

UPDATED

TO Get Android Studio 1.3 follow this steps

1. Open the Settings window by choosing File > Settings.
2. Choose the Appearance & Behavior > System Settings > Updates panel.
3. On the Updates panel, choose the option Automatically check updates for:Canary Chanel.
4. On the Updates panel, select Check Now to check for the latest canary build. Download and install the build when you are prompted.

Then you'll have something like this to update your Androud Studio to 1.3 and with this you can test Android M