Installation failed, invalid APK. in Flash Builder Burrito

I've created an app in Flash Builder "Burrito" for Android Phone. When I run t开发者_如何学Che application there are no project warnings or errors. The .apk was compiled successfully. The emulator is running Andorid 2.2. However, when I push the .apk to the emulator I get "Invalid Apk" error.? Now I don't know how to resolve this problem. Please help me to solve this problem..

Thank you.

Flex 4.5 is under beta, it was released just for demonstration. It is preview release, so wait for stable release.