Incomplete type is not allowed

Debug symbols are used to link memory addresses of binary files (like 0x00007FF9EE1957A6 (UE4Editor-Engine.dll)) with their source code. I’m sure you can find a better and more in-depth explanation online.
If you have them loaded this error will state the .cpp file and the line where the exception has occurred which will give you some insight of what went wrong. It will also allow you a full debug functionality like step-by-step execution on the engine binaries.
That being said, I don’t think you’ll easily get much information out of this. I’m guessing you are trying to access a member function of a deleted object.

Ah ok. Thank you. I will look into downloading the symbols to get a better grasp of what I’m working with.

About this: “Doing that doesn’t cause any errors, but clicking the button causes my editor to crash.”
What button are you talking about? Does it have a custom code in it and what is it?

I’ll start from the top:

First, I went to Settings > Plugins.

Next, New Plugin > Editor Standalone Window.

After saving and restarting the editor, it created a new button on my toolbar that opened up a simple window that just had some sample text.

250101-screenshot-25.png

I opened up VS, and the only code I edited was inside the OnSpawnPluginTab function. As you can see, I simply added an SOverlay and then tried to put an SGraphEditor inside of it. If I don’t include “SGraphEditor.h”, I will get red underlined text at the SNew(SGraphEditor) statement saying that the identifier is undefined. If I do include it, everything looks fine and compiles fine.

However, when I click the button I created, the editor crashes.

250103-screenshot-27.png