The latest update for the Windows 10 Mobile Insider preview build is now ready to be downloaded. The new build number is 10136 and can be grabbed by folks who are a part of the Windows Insider program by going to Settings > Phone Update to check for a new OS update

In a blog post, Windows Insider head Gabriel Aul states that this build is only being offered to users who have Windows Phone 8.1 installed on their phone and are on the Windows Insider Fast ring. He states:

"If you are running the previous build offered to the Fast ring (10080) and you want to get this build you will need to go back to Windows Phone 8.1 via the Windows Phone Recovery Tool first. Once you're up and running on Windows Phone 8.1, go to the Windows Insider app and select Insider Fast again. This is required because of a migration bug affecting upgrades from 10080 to this build so we are not supporting that upgrade path. We know this is a little bit painful but we didn't want to make you wait any longer to get a new build and decided (with help from Windows Insiders following me on Twitter) not to hold for those migration issues to be fixed. Some of you previously had to go through 2 "hops" to get to the latest build on your phone. We've made this better and you will be able to upgrade directly to the latest build in a single hop regardless of which Windows Phone 8.1 build you're starting from."

"If you're on build 10080 and don't want to flash back to 8.1 to get this build, you don't have to do anything. You won't be offered this build but your phone will still be configured for the next one, and we do expect the next build to have the migration issue fixed so you'll be able to upgrade directly."

Aul also mentions one other thing users need to keep in mind with this release:

" At the end of the upgrade the Lock screen will appear frozen without the date and time for up to 10 minutes. Please be patient and let it sit – eventually the date and time will appear and it will allow you to unlock your phone. There is a post-upgrade migration status screen missing, which normally would show you that it was making progress. If you get impatient and restart or mess with locking/unlocking your phone, you'll wind up in a funky state – so just relax and let it do its thing."

Source: Microsoft