attempt to call a nil value — a function or event handler does not exist

What you see

• An action produces a console error and nothing happens
• Only one feature is broken while the rest of the resource works

What usually causes it

• A renamed or removed function after a framework update
• A typo in the function name
• A shared file not listed in fxmanifest.lua, so the function was never defined
• Calling a server function from the client or vice versa

Worth checking first

• Note the named function from the error
• Check fxmanifest.lua actually lists the file defining it
• Check client versus server context

Safe steps, one at a time

• Player-side: report the exact text
• Staff: check the manifest file list first — a missing entry is the most common cause and the easiest to miss

When to stop and ask staff

Always staff.