May 26, 2012, 7:25 AM — If you're having trouble downloading apps from the Windows Phone Marketplace, you just might be a pre-Mango Windows Phone 7 user. Microsoft is now enforcing a rule that only users of Windows Phone 7.5, codenamed Mango, can use the Marketplace in any meaningful way. Without the Mango update you can still browse the Marketplace, but you will start getting error messages if you attempt to download, buy, update, or review an app.
Microsoft originally announced the switch in April. At the time, Microsoft said it needed to enforce the Mango update to improve Marketplace stability and security, as well as making way for new features and improvements to the Marketplace.
It may take a few days for the new change to work its way through the system. So if your non-Mango phone hasn't been shut out of the Marketplace (except for browsing) yet, it soon will be. The majority of Windows Phone users have already upgraded to Mango, according to Microsoft, so the change should only affect those reluctant to make the Mango switch.
Microsoft originally launched Windows Phone 7.5 in September for all Windows Phone users offering new features such as improved voice commands, expanded HTML 5 support, built-in Facebook messaging, improved live tiles, and SkyDrive document editing.