Microsoft released a new Windows 10 Mobile preview today. The new build for phones includes new Cortana languages, improvements to the messaging app, and a diverse set of emoji.

Microsoft issued a warning for this build: A bug causes phones already using the latest preview build “to get stuck at a black screen.” As such, you’ll need to revert to Windows Phone 8.1 first using the Windows Device Recovery Tool, install the Windows Insider app, choose the Fast ring, and reboot your phone. With that out of the way, let’s look at what is new.

Cortana now works for Windows Insiders in Japan, as well as in English for Windows Insiders in Australia and Canada. Microsoft has been working on adding more languages to its digital assistant since last year.

Next, the messaging app now has a text box that can be expanded as you enter text. Previously, the text box could only show two to three lines. An upcoming Windows 10 Mobile build will include Skype integration.

DIVERSE-EMOJI

Last but certainly not least, Windows 10 Mobile now features support for Unicode’s diversity emojis. Microsoft added this capability to Windows 10 for PCs in build 10547, and now it’s finally arrived on mobile as well.

New features aside, this build also fixes the following issues:

  • The Windows Camera app would crash when certain applications launched it to capture a picture.
  • The touch keyboard would get dismissed every time you sent a message, which made sending 2+ texts in quick succession difficult.
  • Swiping away a notification was causing the notification icon to appear top of your screen.
  • Screenshots were not being properly saved resulting in many top social messenger apps such as WeChat, WhatsApp, LINE, WeiBo, and QQ unable to find saved screenshots.
  • You couldn’t launch apps saved on SD cards after reinserting your SD card.
  • Pinch to zoom didn’t work properly in the Maps app.
  • Trying to set a custom ring or text tone for a contact showed a black screen for 10 seconds, then did nothing.
  • Vibrate-only alarms were missing.
  • Call-blocking was broken.
  • Lumia Camera is no longer uninstalled when you update to Windows Mobile 10, though it’s not yet available in the Store for Windows 10 devices so you will need to use the Windows Phone Recovery Tool to return to Windows Phone 8.1 in order to get the app back.

Today’s update bumps the Windows 10 build number from 10536, made available to testers on September 14, to build 10549. Unlike Windows 10 for PCs, which launched on July 29, Windows 10 Mobile hasn’t been released yet — it’s behind in terms of features and polish compared to its PC counterpart.

Build 10549 has the following known issues:

  • After upgrade, you might be missing a few apps. If you experience this, the workaround is to reset your phone.
  • After rebooting your phone, you won’t see notifications, such as new messages, until you unlock your phone for the first time. After that, you should see notifications for new messages just fine. This bug is fixed in a later build.
  • You will be unable to make calls with Skype for Business, WhatsApp and other apps after upgrading to this build. The workaround is to uninstall and reinstall these apps from the Store.

Microsoft plans to launch the first Windows 10 phones in November and roll out Windows 10 Mobile to existing Windows Phone users in December.