I have the same problem on editor version 4.25.1
I solve it by creating child class from FAssetTypeActions_Base type. Then in my module StartupModule function i register asset type actions:
void FSociumSystemEditorModule::StartupModule()
{
IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
GameAssetCategory = AssetTools.RegisterAdvancedAssetCategory(FName(TEXT("SociumSystem")), LOCTEXT("SociumSystemCategory", "SociumSystem"));
AssetTools.RegisterAssetTypeActions(MakeShareable(new FSociumSystemDatabaseActions(GameAssetCategory)));
}
class FSociumSystemDatabaseActions : public FAssetTypeActions_Base
{
public:
FSociumSystemDatabaseActions(uint32 InAssetCategory);
virtual FText GetName() const override;
virtual FColor GetTypeColor() const override;
virtual UClass* GetSupportedClass() const override;