I dont understand what “Module code did not return exactly one value” means. IM using the Roblox engine which is C sharp and cant figure out how to fix this bug

i mostly tried to get help from people close to me for advise but it didnt work. Im trying to get see through red hitboxes to show when you click, also playing a punch combo. The punch combo counts up so if you click once it plays the first attack and stores that information to keep counting up.