Hello experts

I'm trying to perform a Stratification-Multilevel analysis using the hte package. However, when I use any of my variables as a factor, I get the following error:
factor-variable and time-series operators not allowed
r(101);
The code works when my variables are not indicated as a factor, as shown below:
hte sm Filhos_Total sup racac idade ocuppaic migagreg Escpais maeadol urbc [pw=V32039], estcom(poisson) noisily
The problem occurs when I indicate that one of them is a factor, as with the i.ocuppaic variable in the code bellow:
hte sm Filhos_Total sup racac idade i.ocuppaic migagreg Escpais maeadol urbc [pw=V32039], estcom(poisson) noisily

Does anyone know what is happening? Is it a sintax error?