Sounds like a race condition to me. Try delaying your call to StarterGui:SetCore or making repeated calls with pcall
#Error from SetCore call to disable menu reset button
patent cave
It looks like the docs recommend the latter solution:
"It may be necessary to make multiple calls to SetCore using pcall in case the respective CoreScript has yet to load (or if it has been disabled entirely)."
https://create.roblox.com/docs/reference/engine/classes/StarterGui#SetCore
You will ultimately need to yield your thread to allow the respective CoreScript the opportunity to register. task.wait is a good option
tropic nacelle
Sounds like a race condition to me. Try delaying your call to `StarterGui:SetCor...
Ok yeah that explains it better actually Ima try and fix it