Can't upload Android app to device (stale dexed jars)

I have also encountered this problem in Android Studio, from version 2.0 Preview 6 all the way up to 2.0 Beta 3 and none of the solutions mentioned here worked for me.

Turned up it had nothing to do with Instant Run. All I had to do was to increase the AVD's Internal Storage until the following notification disappeared. I also had to perform a data wipe after changing the values.

I disabled Instant run for this project, and problem solved.

Maybe it's a bug in the instant run feature of Android studio 2.0 preview.

Instant Run is a new feature introduced in Android Studio 2.0.

ps: in case you don't find Instant run, its in:

Android Studio --> Preferences --> Build, execution, deploy --> Instant run.

or you can search for it in the preferences tab.

Go to AVD Manager, then in the action section of your device select wipe data. This worked for me, hope it helps....