Second Windows 10 Mobile build finally arrives after 55 days

Update: Microsoft hit a technical snag on getting this build out to all the new phones. Here is their update as of 2:30PM EDT on Friday.

We discovered this morning that there was an error in the database for provisioning record data, which is required for new phones to join the Fast Ring through the Windows Insider app. The team has been working to correct it but the load on the provisioning data servers has made all operations extremely slow. To fix the issue, we are taking the service offline and updating the provisioning record data for all 5100 phone POPs. It will take approximately 2 hours for us to make the update, and validate that everything is working. This is a different service from Windows Update, so Insiders who are currently on 9941 should be able to update their phones if they are already in the Fast ring. If they are in the Slow ring they will encounter the same issue with provisioning data. We apologize for the delay on this and are working to ensure it never happens again.

Ouch - how things very quickly turn from enthusiasm to frustration for Windows Insiders.

Original post continues...

Windows Insiders around the world are eagerly installing a new build of Windows 10 Mobile, the second one in the program, after Microsoft publicly announced two days ago that it would be released today - a full 55 days since the first build was made available back on 12 Feb 2015.

Although it is not standard practice for the company to commit to a date and time for these Insider builds The Ring Master himself, Gabe Aul, did so this past Wednesday during an appearance on Twit's Windows Weekly.

So over the last two days Windows Insiders have been eagerly making sure their supported Windows Phones, see the entire list here, are ready to go.

Unfortunately those with Lumia ICON & 930 are going to be left out of this round due to scaling issues with their handsets.  Aul indicated they should be included in the next build.

The Windows team did release a blog post along side of this build to provide Windows Insiders information about it, any known issues and other info.

What's new:

Project Spartan: An early version of Project Spartan is available in this flight. It uses our new rendering engine to give greater interoperability with the modern mobile web, and includes early versions of Reading View and Reading List. For now, Project Spartan is not the default browser, and exists side-by-side with IE11. You can find it in the All Apps list and pin it to your Start Screen from there. Please send feedback on sites and design. For more details on Project Spartan on the phone – see this blog post. Be sure to also check out this blog post from Joe.

New mail and calendar apps: Outlook Mail and Outlook Calendar are the new built-in mail and calendar universal apps for Windows 10. These new apps bring a fresh UI, with a toggle to freely move between your email and calendar without returning to the Start screen. Outlook Mail includes customizable Swipe Gestures, letting you swipe right or left to take actions like delete, flag, move or mark as read/unread. Also check out the new email authoring experience. Outlook Mail leverages the familiar capabilities of Word to create a richer email experience. You can do formatting tricks like inserting tables, adding pictures and using bullets and text. Outlook Mail and Outlook Calendar connects to Office 365, Exchange, Outlook.com, Gmail, Google Calendar, Yahoo!, IMAP, POP and other popular accounts.

New Phone and Messaging apps: You’ll see our new Phone and Messaging apps in this build. Give them a try and let us know what you think. The Messaging app has a new visual design. You can also easily upgrade from a messaging conversation to a voice call with one click of the phone icon in the new app bar.

New People app: The new universal People app has a new visual design but will continue to be the comprehensive list of all your contacts across the services you care about such as Exchange, Outlook.com, Gmail, Facebook, etc. You’ll be able to easily manage all your contacts and quickly connect with them.

New Maps app: The first preview of our new universal Maps app on phone is now available. Maps offers you the features and tools you need to explore and navigate the world. This includes the best maps, aerial imagery, rich local search data, and voice guided navigation experiences from both Bing Maps and HERE maps, integrated together for the first time into a single app for Windows.

Updated App Switcher: Check out the updated app switcher by pressing and holding the back button on your phone to see your recently used apps. We’ve added support for landscape when invoked from an app being viewed in landscape. For large phones like the Lumia 1520, we’ve introduced a new grid layout so you can be more efficient at switching between apps. And we’ve extended the length of recently used apps to 15.

What is fixed:

Finally - the known issues:

So if you jump in be ready for anything and always keep the Windows Phone Recovery Tool handy as this is beta testing.

Let us know what you think of this new build, 10051, in the comments.

But, wait...there's probably more so be sure to follow me on Twitter and Google+.