Godot 3 to 4 Upgrade: Project Errors After Converting

How to fix it

Try these in order — the most common fix is first.

1. 1. Back up and convert the full project

   Copy steps
   1. Back up the folder or commit to version control; the tool does not back up for you
   2. Update the project to the latest 3.x stable first
   3. Open it in the Godot 4 project manager and choose Convert Full Project
   4. Avoid Convert project.godot Only unless you know you need it
   Did this fix it? Yes No

2. 2. Preview changes from the command line

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   1. Run godot --validate-conversion-3to4 to see the planned changes
   2. Run godot --convert-3to4 to apply them
   3. Files over 4 MB or 100,000 lines are skipped unless you raise the limits
   Did this fix it? Yes No

3. 3. Fix scripts and shaders by hand

   Copy steps
   1. Add super() calls in _ready() and _process() where you relied on parent behaviour
   2. Replace Tween usage with the new Tweeners
   3. Rename .shader files to .gdshader and replace hint_color with source_color
   4. Re-set project settings that were renamed (turn on Advanced to see all)
   Did this fix it? Yes No

4. 4. Re-import meshes and re-setup removed nodes

   Copy steps
   1. Re-import ArrayMesh resources from source files
   2. Set up BakedLightmap, Room and Portal replacements again
   Did this fix it? Yes No

Symptoms

After importing a Godot 3 project, the editor shows hundreds of script errors, shaders fail to compile, nodes are missing or behave differently.

Why it happens

• The converter only renames some nodes, methods and properties
• Shaders need new syntax (.gdshader, source_color)
• _ready() and _process() no longer call the parent version implicitly
• Several nodes were removed and replaced by approximations
• Project and environment settings were renamed or moved

This guide also covers

• godot 3 to 4 conversion errors
• godot convert project 3 to 4
• godot 4 project won't open
• godot upgrade project files
• godot 4 migration errors

The same problem in other apps

All not loading, error messages & connection guides →

• Unity Package Manager Errors (Unity)
• Unreal Engine Out of Video Memory Error (Unreal Engine)

Other Godot errors

• Godot No Export Template Found at the Expected Path
• Godot Android Export Failed (JDK, SDK and Keystore Errors)
• Godot 4 Crashes on Startup: Vulkan Device Errors
• Godot C# Error: Godot.NET.Sdk or .NET SDK Not Found
• Godot Shader Compilation Stutter and Lag on First Run
• Godot Web Export Not Working: SharedArrayBuffer and Blank Page
• Godot Invalid Access to Property on Null Instance Error
• Godot Exported Game Blocked on macOS: Developer Cannot Be Verified