WhatsApp and more may be left behind when Microsoft launches its next attempt at Windows on the phone.

As Windows Central has been reporting on for several weeks now, Microsoft is not done with its mobile efforts, and internally has already started work on its next attempt at a Windows powered phone platform. For a while now, I've been hearing whispers that Microsoft's next attempt at Windows phone won't include support for older, Windows Phone 8.1 Silverlight based apps, and today more evidence for that has come forward.

Thanks to a screenshot from @gus33000 on Twitter, we can now see that Microsoft has already developed a temporary popup for when a user tries to open a Silverlight app on a build that doesn't support it. The popup says "Silverlight apps are no longer supported on this version of Windows." What does this mean for you? It means that when Microsoft is ready to launch its next attempt at Windows phone, older apps like WhatsApp and Slack will not work.

Now, this doesn't necessarily mean current Windows phone devices will lose support for these apps. It's likely that Microsoft's next attempt at Windows phone probably won't even launch for existing handsets. Sources suggest Microsoft is going to start afresh with Windows phone, with UWP being front and center. This is a good thing, as it helps remove older apps that aren't using any new Windows 10 APIs, and forces developers to update their apps or be left behind.

This change should also hopefully directly benefit Windows 10 desktop users too. WhatsApp, for example, now has a choice. Either continue supporting its Silverlight app for Windows Phone 8.1 and Windows 10 Mobile devices, or build a UWP app and bring it to Windows 10 Mobile, Microsoft's next attempt at Windows phone, and 500 million Windows 10 PCs. I think the smart choice is pretty obvious.

Windows Central will have more details regarding the future of Windows phone soon. In the meantime, what do you think of this rumored change? Let us know in the comments.