I am working on a multi-level meta analysis. The model we have has a continuous Level 1 outcome, a continuous Level 1 predictor, and a continuous Level 2 predictor. I have been able to easily fit a fixed effects model to the data in MPlus, and would like to now fit a random effects model. However, I am running into serious issues with this model, and in looking more closely at the available examples for such analyses I have noticed that they all only use Level 1 predictors. Indeed, when the Level 2 predictor is excluded, the random effects model runs just fine. I am wondering if it is possible to estimate such a model including a Level 2 predictor, and if you might be able to point me to any references regarding this type of analysis?