Operating system: windows 10
Graphics card: NVIDIA GeForce GTX 960M
Short description of error
I cannot assign shortcut to subdivision surface.
Exact steps for others to reproduce the error
It was keep adding a new shortcut key and couldn't fix by going to Modifiers > Add Modifier > Subdivision Surface and Right clicking and Assign Shortcut. It should override the setting not keep stacking.
How I fixed: Go to Edit > Preference > and search "add modifier", I found multiple shortcuts assigned to Subdivision Surface.