# \[UE4 Launcher\] **URL:** \ **Category:** Getting Started & Setup\ **Tags:** launcher, unreal-engine, Installation, question\ **Created:** [January 9, 2015, 8:09am UTC](https://forums.unrealengine.com/t/ue4-launcher/303433 "2015-01-09T08:09:46Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![phungdinhdung](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@phungdinhdung](https://forums.unrealengine.com/u/phungdinhdung)\ **Post date:** [January 9, 2015, 8:09am UTC](https://forums.unrealengine.com/t/ue4-launcher/303433/1 "2015-01-09T08:09:46Z")
Hi Epic, I was working with UE4 4.7.0. Then I follow the tutorial (the link: [A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums](https://wiki.unrealengine.com/Light_Propagation_Volumes_GI) ) to enable real time GI by go in to the Engine\>Config\>ConsoleVariables and add in the r.LightPropagationVolume=1 I saved the file and open the launcher again. Then suddenly I can not access to UE4 any more. Please help me! ![26096-ue4sunquestion.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/8/d/68dd670820ee02b040b722db280f8522a08fa258.png) ---
**Author:** ![eXi](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/exi/32/906583_2.png) [@eXi](https://forums.unrealengine.com/u/eXi)\ **Post date:** [January 9, 2015, 10:45am UTC](https://forums.unrealengine.com/t/ue4-launcher/303433/2 "2015-01-09T10:45:48Z")
Hey, have you tried removing this line again to check if this is really causing the problem? (: ---
**Author:** ![TJ\_V](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/tj_v/32/1008648_2.png) [@TJ\_V](https://forums.unrealengine.com/u/TJ_V)\ **Post date:** [January 9, 2015, 3:47pm UTC](https://forums.unrealengine.com/t/ue4-launcher/303433/3 "2015-01-09T15:47:13Z")
Hi phungdinhdung, There is a new update out for the 4.7 Preview. You will need to download it in order to keep working with it. If you still have this issue once you’ve updated, post back here and let us know. Cheers, TJ ---
**Author:** ![phungdinhdung](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@phungdinhdung](https://forums.unrealengine.com/u/phungdinhdung)\ **Post date:** [January 19, 2015, 4:27am UTC](https://forums.unrealengine.com/t/ue4-launcher/303433/4 "2015-01-19T04:27:22Z")
Hi, 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? ![27125-ue4launcher.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/8/c/68c44e2b6e7bdf3de943cd314aa2cff6c9fa233f.png) One more thing is that I want to download the demos and showcase form the Learn but I couldn’t. Here is what it shown. ![27126-ue4learn.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/4/8/4/4847d618ec61284bf3656c4aa4f79f6874cc91f1.png) I have just gone directly to my old project and click on the uproject to try access the editor manually, but is says " No Unreal Engine installation is found …" ![27128-ue4engine.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/a/b/3/ab33616dc5de65e53c057f7cd49a346da9a4dfb2.png) ---
**Author:** ![TJ\_V](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/tj_v/32/1008648_2.png) [@TJ\_V](https://forums.unrealengine.com/u/TJ_V)\ **Post date:** [January 19, 2015, 2:27pm UTC](https://forums.unrealengine.com/t/ue4-launcher/303433/5 "2015-01-19T14:27:12Z")
This is odd, the Launcher version should also say ‘Preview 3’ under the version number. ![27171-launcherpreview.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/b/8/7b80afefbebda41bbf55d2209a2093400e9d942e.jpeg) First off, try verifying the version. On the 4.7.0 card, click the yellow down arrow. Choose ‘Verify’. If this doesn’t work, take a look at these troubleshooting steps in the ‘Launcher is Unable to Download Content’ section of this link. > **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)** > > After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — https://unrealcommunity.wiki/! You will be able to find content from... Let me know how it goes. ---
**Author:** ![phungdinhdung](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@phungdinhdung](https://forums.unrealengine.com/u/phungdinhdung)\ **Post date:** [January 20, 2015, 7:53am UTC](https://forums.unrealengine.com/t/ue4-launcher/303433/6 "2015-01-20T07:53:38Z")
thanks for you reply TJ Ballard, 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. ![27274-screenshot_ue_01.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/d/f/5/df5c267279dcb8d1bf07d8b8e51f76cc71c6c9b3.jpeg) ---
**Author:** ![TJ\_V](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/tj_v/32/1008648_2.png) [@TJ\_V](https://forums.unrealengine.com/u/TJ_V)\ **Post date:** [January 20, 2015, 2:45pm UTC](https://forums.unrealengine.com/t/ue4-launcher/303433/7 "2015-01-20T14:45:31Z")
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. > **[Unreal Engine 4.7 Preview](https://forums.unrealengine.com/showthread.php?54610-Unreal-Engine-4-7-Preview)** > > This is an early preview of the upcoming 4.7 release. This Preview is only available with the binary editor via the Epic Games Launcher. We are modifying our preview process to release earlier in the development cycle so our developer-community can...