Mulitvariable Analysis

Hey Team,

I need to perform a multivariable model to test if the mean test score (a scale variable) is different for a group of participants depending on their education level and age group (both ordinal variables). So Test score would be the dependent variable and education level and age group would be the two fixed factors.

I tried putting this into SPSS in General linear model -> Multivariate. But it doesn't let me press ok and continue. Would anyone know what I am doing wrong? Maybe this would be the wrong test? Any ideas on what I could do instead?

Thanks alot!