Dear All,

Apologies in advance if I am not including all necessary information, this is my first time posting here.

I am trying to plot a cross-level interaction of a categorical and a continuous outcome in a mixed model. I keep getting the following error with marginsplot: "using variable VACANT5 as a factor variable and a regular variable is not supported" and I am not sure how to resolve this.

My code for the model is as follows (note VACANT5 is a dichotomous variable and age is continuous):
mixed BMI age VACANT5 VACANT5#c.age|| CD:age, var covar(un)

I then tried to run margins for the interaction term:
margins VACANT5#c.age

but kept getting the error: "only factor variables and their interactions are allowed"

so I ran it as follows:
margins VACANT5, at (age=(18(2)100))

this worked, but I still can't get it to plot (getting the error listed above).

Any ideas of what I'm doing wrong or how else to get this to work?

Thanks!