[HELP] Unreal Engine C++ class not saving/compiling changes after reopening project

Development Programming & Scripting
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1

Hi everyone,
I’m having a strange issue with Unreal Engine and a custom C++ class I created (a class library with static functions). Here’s what’s going on:

The Problem:

  • I created a C++ class (let’s call it MyGameplayFunctions) with some static functions.
  • I compile the code in Visual Studio → then click “Compile” in Unreal Engine → everything looks fine at first.
  • BUT when I close Unreal Engine and reopen the project:
    • My newly added functions are gone or not recognized in Blueprints.
    • The class seems to revert to an older version, like it never saved the changes.

Packaging Error

When I try to package the project for Windows, I get an error like:

bash

CopiaModifica

Could not find a function named "SetVariableaDuringGameStaret" in 'BP_PlayerMani'

This is a Blueprint node calling one of the functions I added. The function existed before I closed UE5, but now it’s gone from the engine’s view.

What’s strange is:

  • My very first test function in that class (which takes a string input) still works fine and can be packaged.
  • All functions added after that are not detected anymore.

What I Tried

  • Rebuilding the solution in Visual Studio.
  • Compiling in UE5 after changes.
  • Deleting Intermediate, Binaries, and DerivedDataCache folders before reopening.
  • Checking Build.cs to ensure the class is in the right module.

What could be causing this?

  • Why does the engine “forget” the newer functions?
  • Why is only the first function retained, even though the class compiles fine?

Any advice or pointers would be super appreciated! Thanks in advance

2

Please provide the header file in question, either via screenshot or pasted as “preformatted text”, and a screenshot of the call site (in the blueprint graph I presume).

3

Hello, I found the solution!
Basically, I set the startup project to compile all my classes.
I don’t know why, but for some reason Unreal Engine 5 wasn’t remembering the files and classes I had created before closing it.
I fixed it by enabling auto-compilation when opening UE5.
Now everything works fine, and I’m also able to create the build package to play the project outside the editor.