Microsoft has now detailed the problem on the Windows Phone Blog and there’s good news and some bad news. The good news is they acknowledge that there is an issue and they even know what is causing it. As it turns out, there are some problems with certificates for new apps published in the Marketplace within the last week.

We’ve been trying to figure out exactly why some users have the problem while others, including ourselves, do not. Just as interestingly, we wanted to know which apps were exhibiting the error.

Ever since WhatsApp was pulled and then re-released this past weekend, we have had a small deluge in complaints from users that they cannot install the update. Instead, they are greeted with the above error message, resulting in user frustration. What’s more, uninstalling the app, resetting the phone and dancing around in a circle did not fix the problem either.

Windows Phone apps that were already on the Marketplace are fine, it is only ones that went through after the AppHub to DevCenter change. What’s more, it’s only a subset of Windows Phone owners—those that have a non-Mango device. In other words, first generation Windows Phones that were later updated to Windows Phone 7.5 Mango are the only ones who cannot get certain apps right now. Those apps are the New York Times, WhatsApp and Translator, to name a few.

This explains why we haven’t seen the issue ourselves as we’re all running new hardware.

Changes to the new Dev Center have caused a few issues

As we mentioned, Microsoft is aware of the problem and a fix is expected soon. Until then, Windows Phone users who cannot update their apps are encouraged to not uninstall them as this will disable their ability to get that app until this issue is resolved (so keep WhatsApp at the previous version). For everyone else who is not having any problems, there is no need to worry, as you will continue to be oblivious to any of these problems.

There is also an issue here for developers. Those who have recently submitted app updates may have noticed that the process is taking a long time. In short, until this situation is resolved with the bad certificates, Microsoft is holding all app certifications so as to prevent further instances of non-updatable apps for consumers.

To summarize, Microsoft has acknowledged that there is an issue with bad certificates on a small number of apps. What’s more, these apps are only having a negative impact on non-Mango phones—that is if your phone shipped with Mango or higher, you’re okay. Microsoft is working on a fix and we’ll keep you posted on when that goes through. For now, hold onto your apps and developers, standby as Microsoft gets new certificates for your app updates.

Source: Windows Phone Blog; Windows Phone Developer Blog

Update: Microsoft as created an area at Microsoft Answers to better address consumer questions on this issue. Additionally, a similar area has been created for developers here at the MSDN forums.