I am receiving this error message: "Observed variable on the right-hand side of a between-level ON statement must be a BETWEEN variable." I am using MLR for two-level models in which two level-2 random intercept outcomes are predicting the level-2 random intercept for a level-1 binary outcome. Notably, I get this error when the level-1 binary outcome is properly denoted as categorical, but not if I pretend it is continuous instead.
I have tried a work-around I found on another post, which is to create level-2 factors that are perfectly indicated by the variables generating the error message and use those as the predictors instead, but the model will not converge, even with montecarlo integration.
Any help you could provide would be greatly appreciated!