I am trying to analyze the difference in means between the variable "age" and "happiness". I am trying to run a One-Way ANOVA but whenever I add "happiness" as DEPENDENT VARIABLE and "age" as GROUPING VARIABLE, I get a message that says "not enough observations".
I have a sample of 241, so I don't know why these message pops up.
Any help will be greatly appreciated

PS: please, let me know if I should be using a different test, I have very little idea about Statistics. Happiness is measured on a 1-10 scale (1 being "very unhappy" and 10 being "completely happy").