Won’t write anything (silent fail):
Settings->SaveConfig(CPF_Config, TEXT("DefaultEngine.ini"));
Settings->SaveConfig(CPF_Config, TEXT("RandomName.ini"));
Settings->SaveConfig(CPF_Config, TEXT("Config/DefaultEngine.ini"));
Will work:
Settings->SaveConfig(CPF_Config, *Settings->GetDefaultConfigFilename());
GetDefaultConfigFileName() returns not only a file name but it’s directory path:
“…/…/…/…/…/Unreal Projects/YourProject/Config/DefaultEngine.ini”