Can't compile code or refresh code in-editor? (Disabled compile button)

Yesterday i was just adding some code to an actor in visual studio and hot reloading as usual when i noticed my code wasn’t updating in-editor? no problem, i’'ll just close UE and reopen it… Same problem except now i notice not only is my code not updating but the compile button is permanently disabled? (see picture below)

At this point i’ve been doing everything i can think of to reset some broken cache/temp files, even to go as far as to uninstall UE 4.9.2 and reinstall it but same issue. I’ve also opened some other projects in 4.9.2 and they all have the same disabled compile button? So… its not the project and also not the engine that’s causing the bug?

Some info:

Engine version : 4.9.2
Engine type: From launcher (Not source code version)
Reproducible in clean c++ project: Yes

I’ve opened a copy of my project in 4.10.4 and the bug is gone but i’m not willing to move my project to 4.10 yet unless i absolutely have to.


I fixed my problem by deleting the engine files manually in C:\ProgramFiles\UnrealEngine\4.9

Deleting the engine through the launcher didn’t fix it like i said but this way it did.

I would recommend not using that button at all, since hot reload can **** things up really badly. When youre in Visual Studio and are ready to compile,
close UE4, rightclick on your project in the solution viewer and click “Build MyProjectName” (should be the first button). That compiles everything, and if theres an error you also See IntelliSense showing you that instantly. If it is finished you can start UE4 with your project again and the new code is loaded!

But isn’t that a very slow process than clicking a button?

Not really, here you do two clicks…