Is it possible to run the Unreal 4 editor in off line mode or do you have to be on line to use it?
You do not need to be online in order to use the editor. To open the launcher while offline, click the ‘Use Offline’ button when signing in to the launcher. You can also open the editor without using the launcher, by opening the .uproject file in your project folder.
Ahh ok then and thank you for the info.
I can not get to start in off line mode, my launcher keeps install prerequisite files to start up and when the launcher is starting up I can’t switch it to off line mode and when I tried to open my project file I got ask for a program to open it with, I looked in the Unreal 4 editor folder and there is no Unreal 4 editor exe
Make sure it has downloaded all files.
I have downloaded the editor, you mean I need to add the updates?
Okay, you have UE4 4.10?
Then make sure to launch it whilst the launcher is connected.
Yes I have UE 4.10, can that be used in off line mode after it’s started on line?
Yes, I use it offline all the time.
But just make sure it works…
Ok then I’m DLing the updates so that should fix things, but how do I get the launcher to work off line I have all the files need to run UE 4.10 but the launcher keep wanted to start on-line to verifiy and install pre-reqs to get things started, I did a clean install of the launcher and UE 4.10 from the epic site.
After everything is downloaded, All you have to do is start the launcher.
And press the ‘Go Offline’ (It comes up when it tells you to sign in.) button then it will start the launcher in offline mode!
Ok then thanks for your help 
Hope everything works out for you!
Happy UE4ing… I guess?
Thanks I hope all goes well for you in your game making and or editing.