Unreal Engine "Project 'Engine' load failed". UBT log: "Exception while generating include data for Target:UnrealEditor ..." – Support | JetBrains

Problem

After upgrading the Engine version and opening an Unreal Engine game project, game and engine projects don't load.

Problems view states "Project 'Engine' load failed" (same for a game project).

"Failed to generate project model definition files for the project model" message is seen if select the "Project 'Engine' load failed" row in the Problems view.

Resolution

Check the build output and UnrealBuildTool logs. Look at the Log_GPF.txt log. The same output can be got by opening the project in Unreal Editor and selecting Tools | Refresh Rider Uproject Project. If you see an exception like this:

System.ArgumentNullException: Value cannot be null. (Parameter 'element')
   at System.Attribute.GetCustomAttributes(MemberInfo element, Type attributeType, Boolean inherit)
   at System.Reflection.CustomAttributeExtensions.GetCustomAttributes[T](MemberInfo element)
   at UnrealBuildTool.ModuleRules.IsValidForTarget(Type moduleType, ReadOnlyTargetRules targetRules, String& invalidReason) in D:\Path\To\Engine\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\Configuration\ModuleRules.cs:line 1636
   at UnrealBuildTool.UEBuildTarget.AddAllValidModulesToTarget(ILogger Logger) in D:\Path\To\Engine\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\Configuration\UEBuildTarget.cs:line 3938
   at UnrealBuildTool.UEBuildTarget.PreBuildSetup(ILogger Logger) in D:\Path\To\Engine\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\Configuration\UEBuildTarget.cs:line 3403
   at UnrealBuildTool.UEBuildTarget.Create(TargetDescriptor Descriptor, Boolean bSkipRulesCompile, Boolean bForceRulesCompile, Boolean bUsePrecompiled, UnrealIntermediateEnvironment IntermediateEnvironment, ILogger Logger) in D:\Path\To\Engine\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\Configuration\UEBuildTarget.cs:line 1392
   at UnrealBuildTool.RiderProjectFile.WriteProjectFile(List`1 InPlatforms, List`1 InConfigurations, PlatformProjectGeneratorCollection PlatformProjectGenerators, JsonWriterStyle Minimize, ILogger Logger) in D:\Path\To\Engine\Saved\CsTools\Engine\Source\Programs\UnrealBuildTool\ProjectFiles\Rider\RiderProjectFile.cs:line 119
Building UnrealEditor - RiderOnUnreal54Editor - Win64 - Development

The issue might be caused by incompatibilities between custom plugins and changes in new UE version. Check if you have any custom plugins installed to the engine. If there are such, either drop them nor try moving custom plugins from the engine into the project (from {UE X.X root}\Engine\Plugins to {project root}\Plugins). Then check if that helps. There is a similar report on the EpicGamesCommunityForum: Exception while generating include data for UnrealEditor: System.ArgumentNullException: Value cannot be null. (Parameter ‘element’)