Dear all,

I am teaching to students who are using STATA 17 and I have STATA 16 on my machine.

Weirdly enough, when estimating a model using "mixed" and specifying

mixed y x1 x2 x3 || id:, nocon res(ar6,t(t)) stddev robust

I get correct results, while they get the error message "error obtaining scores for robust variance".

Any ideas on what happened between STATA 16 and 17 that might affect this?

Thank you!