Apple just a little while ago released the fourth beta of Mac OS 10.12 Sierra, which is intended for all registered developers. New, corrective beta comes exactly two weeks after the third beta version and more than a month and a half after the first beta that Apple introduced at WWDC 2016 and released shortly after the conference. If you already have a previous beta version installed, just open the app Mac App Store and tab Updates MacOS Sierra 10.12 Beta 4 download and install.
If the new operating system for Mac computers do not but would like to try it, then you either pay developer account at developer.apple.com or you can consume our guide , which is described in detail how to install MacOS Sierra without developer take account. The last option is to register on the website beta.apple.com and wait for a new public beta, which should see the light of tomorrow.
Apple is again not shared, which updates Mac OS 10.12 Beta 2 brings the Sierra, but expect to bug fixes and maybe some new features. About possible changes in the system will inform you.
[Update 1x:] Corrections and known bugs in macOS Sierra beta 4: