Thanks to some recent issues to what I can only presume to derive from the launcher update this past week, Unreal Engine 4 launcher versions now no longer function properly with the majority of Unreal Engine 4 projects. I have been able to reproduce this on nearly every computer I own in my office. So far, I have tried both version 4.26.2 and 4.27.2 and the majority of my projects running those versions are instantly met with the critical “Failed To Launch Editor” message.
This is because Epic has completely screwed up the editor executable pathing with their recent launcher updates, and now in order to open those projects, you have to manually open them with the UEEditor.exe from your binaries of the engine version it’s supposed to be opening with every single time. You can also set the default app to that editor.exe, but keep in mind you won’t be able to use both UE4 and UE5 simultaneously using shortcuts of any kind.
What is odd, is that some projects that I have C++ in running 4.26.2 have in fact managed to launch fine with no issues from their original shortcuts, without changing any executable to open them with. I have not done my research on this, but I would have to take a bold guess in saying source versions of the engines probably work with no issues right now.
I have no idea what the true cause of this is, and my claims of what are only irritated assumptions - but this is not cool for us Unreal Engine users who still like to use both UE5 and UE4. I hope this is fixed soon by Epic, and that they also pay more attention to what they are doing to the launcher because this whole past week it’s been a sh*t show with it if I am being honest.
If anyone else has further information or news on this I’d love to hear it. But for now, it’s an issue with an annoying workaround that needs to be fixed.