When you encounter the "unreal engine missing script" error, it is generally due to one of the following reasons:
Corrupted or Missing Files: The most common cause is that some of the blueprint script files or C++ source files are corrupted, deleted, or otherwise missing from the project directory. This might happen after a version control update, a failed merge, or a disk error.
Broken References: If you've recently moved or renamed scripts, classes, or assets within your project, references to these items may not have updated correctly. Unreal Engine relies on a strict referencing system and if an asset is moved without updating its references, errors can occur.
Plugin or Module Issues: Sometimes the error could be related to a plugin or a module that is not loaded properly. If the missing script is part of a plugin or an external module, the engine might not be able to find the relevant files.
Outdated Cache: The Derived Data Cache (DDC) or other cached data could be outdated, causing the engine to look for scripts in the wrong location.
Compilation Errors: If you have recently compiled or recompiled your project's source code and there were errors during this process, necessary script files might not have been generated correctly.
Project Configuration Issues: The project settings might be misconfigured. For example, if the build configuration is incorrect or certain necessary modules are not included in the build, scripts might be missing.
To resolve the "unreal engine missing script" error, you can try the following solutions:
Verify Files: Use the version control system to check for any missing or changed files. Restore any missing files and ensure all changes are intentional and correctly merged.
Fix Broken References: Use the 'Fix Up Redirectors' feature within the Content Browser to repair broken references. Also, manually verify that all renamed or moved assets are properly referenced.
Re-enable Plugins: Check the Plugins window to make sure that all required plugins are enabled. If you suspect a plugin issue, try re-enabling it or reinstalling the plugin.
Clear the Cache: Clear the Derived Data Cache by deleting the contents of the
Saved folder in your project directory (make sure to back up your project first). Then, regenerate project files and restart the Unreal Engine Editor.
Recompile the Code: Open the project in your IDE (e.g., Visual Studio) and attempt to rebuild the entire solution. Pay attention to any compilation errors and fix them before trying to open the project in Unreal Engine again.
Check Project Settings: Go through your project settings to ensure everything is configured correctly. Under the Build configuration, make sure all necessary modules are included and your target platforms are correctly set.
Regenerate Project Files: Right-click your
.uproject file and select 'Generate Visual Studio project files' or use the 'Refresh Visual Studio Project' command from within Unreal Editor's File menu.
If after trying these steps the problem persists, consider reaching out to the Unreal Engine community or forums for further assistance, as the issue might be more complex or specific to your project setup.