I tried to uninstall ue4 from my machine and start to download it back again. Now the Yellow Button is activated with “Launch 4.7” . However, when I click on Launch 4.7, nothing happen, it does not entering the Editor.
One more thing is that when I re install, ue4 launcher does not recognize the old projects, so is it possible that I can add the old projects back to the laucher?
I still can not access the 4.7.0 version, still nothing happen when i click on it. So I decided to download the 4.6.1 version and it works properly. Even the old projects created with 4.7 also appears. In short, the 4.6.1 is really stable. I dont know what really happen with the 4.7. Maybe i will stick with the 4.6.1 until a more stable version out.
The 4.7.0 Preview is only rolled out for community testing. It is essentially a beta of the next release. If you are working on a project, I would make sure that you stay on an stable build and only upgrade to a newer stable version if you need something that was fixed or implemented in that build.
Keep an eye on the Forums, we always post release notes for each new version. Here is a link for more info on our Preview builds.