Microsoft's shut-down of the Windows Mobile 6.x Marketplace wasn't the only change, happened this week. As announced earlier, Microsoft is now requiring Windows Phone 7.5 on phones to download, buy, update or review apps in the Windows Phone Marketplace. As mentioned, this change applies to both the phone and web Marketplace storefronts. Since most Windows Phones are already running Windows Phone 7.5 aka Mango, which was released last fall, most users won't notice anything different about how the Marketplace works. However, devices with an earlier version of Windows Phone are now receiving an error message when they try to download a new app, or update one you already own.
If you do get the error, it's time to finally install the free Windows Phone 7.5 upgrade via the Zune desktop client!
Cheers ~ Arne