Cannot build a platform-specific XAML Browser Application in visual studio

I am trying build XBAP by setting platform target to x86, and I got the following error.

Cannot build a platform-specific XAML Browser Application. If HostInBrowser property is set to 'True', either do not se开发者_高级运维t the PlatformTarget property or set it to 'AnyCpu'

Is there any reason why this is disabled?

It's disabled because you can't control your user(s) browser. XAML Browser Application are browser independent.

You can avoid this error by targeting Any CPU on configuration manager.