How can I refresh project in UE5?

when i click the [Refresh Project] button in UE5


An error occurred while trying to generate project files.

Setting up bundled DotNet SDK
/Users/Shared/Epic Games/UE_5.1/Engine/Build/BatchFiles/Mac/…/…/…/Binaries/ThirdParty/DotNet/6.0.302/mac-x64
Running dotnet Engine/Binaries/DotNET/UnrealBuildTool/UnrealBuildTool.dll -projectfiles -project=/Users/chan/Documents/Unreal Projects/Udemy/ToonTanks/ToonTanks.uproject -game -rocket -progress
A conflicting instance of UnrealBuildTool is already running.

please give me a solution…
thank you.

ps. i already download SDK in this url