Publish Android App is disabled when select Use Shared Runtime

Hi all,
Today I get a problem when trying to publish a project to apk file.
If I check the Use Shared Runtime check box, the Publish Android App menu will be disabled.
Then if I uncheck the check box, the menu will be enabled.
In both cases, I already set the Android Project as startup project, and already select it in Solution Explorer
Anyone who know the solution?
Thank you.