I have a problem regarding a regression discontinuity design. I use panel data, where I have two years, and some schools have data for the two years. The dataset is in the long form. The dependent variable is var1, the independent variable is var2 and the running variable is var3. Var3 contains of 3 values, which is 0, 1 or 2. When var3 has the value 1 or 2, var2 gets the value 1 (otherwise 0). Var1 is a variable that has values in percentages. I would like to make a rdplot. I have installed rd robust (net install rdrobust, from(https://raw.githubusercontent.com/rd...t/master/stata) replace). Then I sorted the dataset according to var3. But when I use: rdplot var1 var3, c(1), I get an error: rangen(): 3351 argument has missing values
<istmt>: - function returned error

I already dropped all the observations that have missing values. But that didn't solve the problem. How can I make a rdplot?

Thanks in advance.