Problem, It's not accessing the player/playergui
This is a regular script in the worksapce
script.ActivateRespawn.OnServerEvent:connect(function(player)
print(34134) -- Only thing that is printed
player.PlayerGui:WaitForChild('ActivateRespawn').Disabled = false
wait(.5)
player.PlayerGui:WaitForChild('ActivateRespawn').Disabled = true
print(34134)
end)

2 comments
Seems like the child is never found, does 'ActivateRespawn' exist (with that exact spelling) in the PlayerGui?
yes