Application has stopped immediatly after starting on Android

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http://stackoverflow.com – I am desiging a simple webBrowser with webview, in VS 2010, when I compile program, it's okay, and even when I run it in emulator it works all right and I see the window and button, but when I install on device, immediatly says 'stopped' and closes the application without showing anything. I use API 8 to compile and install unsigned version and try to install it on android 4 or higher. Appendix: When I run project in xamarin, it doesn't create apk file, nevertheless I did all configuration said in documention. What should I do to run on device or when can I compile it for once? (HowTos)