react query optimistic update "old is not iterable" why this error occured

Updating profile is working fine, but optimistic update is not working properly. An error occured 'old is not iterable'. How to fix this ?

  export const useUpdateProfile = () => {
  const queryClient = useQueryClient();

  return useMutation(updateProfile, {
    onMutate: async (newProfile) => {
      // Cancel any outgoing refetches (so they don't overwrite our optimistic update)
      await queryClient.cancelQueries("user-profile");
      // Snapshot the previous value
      const previousProfile = queryClient.getQueryData("user-profile");

      // Optimistically update to the new value
      queryClient.setQueryData(["user-profile"], (old) => [...old, newProfile]);

      // Return a context object with the snapshotted value
      return { previousTodos };
    },
    // If the mutation fails, use the context returned from onMutate to roll back
    onError: (err, newTodo, context) => {
      queryClient.setQueryData("user-profile", context.previousProfile);
    },
    // Always refetch after error or success:
    onSettled: () => {
      queryClient.invalidateQueries("user-profile");
    },
  });
};