Microsoft has just rolled out to Windows 10 Mobile build 10136 to the Fast ring of updates. In the fourth build, the software giant is including a number of features and enhancements of the previous build. However, because the new preview is being release to the Fast ring, it also means more bugs, issues, and fewer workarounds.

Although, Microsoft is making available Windows 10 Mobile build 10136 to Windows Insiders, the company warns that there are a number of known issues that everyone should be aware of before installing the new build. Below, you’ll find the list of all the known issue for build 10136:

  • After upgrading, you will still see duplicate tiles for apps like Search and Phone under All Apps.
  • If you have too many PIN unlock attempts, you’ll see the “enter A1B2C3” reset experience. However, there is an issue in this build where after you enter the code you won’t see the PIN pad. The workaround is to press Emergency Call after entering the code, then press Back and you’ll be able to enter your PIN.
  • Microsoft recommends disabling the double-tap-to-wake feature on some Lumia devices by going to the Settings app then Extras > Touch > Wake to prevent any accidental PIN unlock attempts.
  • There is an issue that may cause Skype not to work after upgrade. The best workaround is to uninstall Skype on Windows Phone 8.1 before you upgrade to this build and then reinstall it after upgrading. If you miss that step though, you can usually resolve by uninstalling it and reinstalling from the Store once you’re on 10136.
  • If you’re having issues installing new Language Packs in this build, see this forum post.

In addition, Microsoft advice to read and follow the upgrade carefully, as there is a big bug in Windows 10 Mobile build 10136 that cause the upgrade to fail for users upgrading from build 10080. The company recommends that users on Windows 10 Mobile build 10080 to roll back to Windows Phone 8.1, and then install the Windows Insider app, and configure the phone to receive the new build via the Fast ring.

  • Microsoft recommends disabling the double-tap-to-wake feature on some Lumia devices by going to the Settings app then Extras > Touch > Wake to prevent any accidental PIN unlock attempts.

While there is clearly a number of issues with this build, it’s also worth pointing out the operating system is also taking shape, as Microsoft plans to release the mobile operating system sometime in September of this year.

Source Microsoft