Trying to run a GMM and introduce one covariate (BMI) . If I do not add BMI into the USEVAR section, it cannot read the variable and I get the error message: "Unknown variable(s) in an ON statement: BMI"
If I do add my covariate into the USEVAR list, I get another error message: "Variable is uncorrelated with all other variables within class: BMI"
Thank you so much, it worked! Now that I am reading the syntax I was copying from I realise that there was in fact 1 less class in the "MODEL" section than they were testing for - can't believe I missed that.