C++ classes are disappearing in editor, but they are appearing in Visual Studio?!

[SemiSonicMiraculer]

Hello.
I have a strange and absurd phenomenon on UE5.

I created C++ class in Unreal Editor, then I edited it in Visual Studio. As far as I planned to try to make animated UMG thing on C++, I reparented User Widget Blueprint to my C++ class. And after my several tests, Unreal Editor crashed. But IDE was opened. And I restarted UE5 (with automatically sending a report) And then… The biggest programming absurdity I have ever encountered.

So let me show you some screenshots of my problem. Just look at the screenshot from Visual Studio.

Full version of this screenshot:

And let’s have a look at the situation from Unreal Editor.

Full version of this screenshot:

After restarting the project and trying to open User Widget Blueprint, I get such error message:

Widget Blueprint could not be loaded because it derives from an invalid class.
Check to make sure the parent class for this blueprint hasn’t been removed!

It’s strange, isn’t it?

Then, note: I’m using Unreal Engine 5.1.1 from Epic Games Launcher and Visual Studio 2022 Community Edition.
And yeah, I know that there are many similar topics and questions on Unreal Engine Forums. But even refreshing VS solution didn’t help me in this problem.

Should you know how to solve that strange and absurd problem, please don’t hesitate to leave your solution or comments about that.

I hope that problem is soluble and this bug could be fixed on next versions of UE5.

[TuppsMidel]

I had the same issue. Solution from here worked for me.

My C++ classes disappear after reopening the project. Why?

I have created the actor MyEarth which loads a staticmesh from Content Directory and the class MyGameModeBase (derived from GameModeBase) which spawns an instance of MyEarth in a position. Everything works fine, the actor appears as expected. But,after saving eveything,when i reopen the project, my c++ classes MyEarth and MyGameModeBase are no longer in the C++Classes Folder of the Content Drawer of the Editor,and when i run the project,nothing appears and no MyEarth actor in the Outliner. Obv…

[SemiSonicMiraculer]

Well, I deleted Intermediate and Binaries folders. I got warning.

Then, I got that error

But then, Unreal Engine was launched successfully, and I finally have access to my C++ classes))

Thank you very much <3

I hope that bug will be fixed on UE 5.1.x or 5.2

[PresumptivePanda]

Hi there @SemiSonicMiraculer, hope you’re well!

This topic has been moved from International to Programming & Scripting: C++.

When posting, please review the categories to ensure your topic is posted in the most relevant space.

Thanks and happy developing!