Insiders moving from Fast ring to either Slow or Release Preview rings may experience an install failure with error code 0x80073715 when they are offered KB4015583 (Build 15063.14). The error is understood and expected as we released a different version of the KB to Slow and Release Preview rings which fails to install on the version of the KB that went out to the Fast ring. As long as your PC is showing 15063.14 as the OS Build number then you are running the right OS bits. So sit tight! You don’t need to do anything.
Windows Insider Team