Fixed. There are two bugs actually: 1. If you enter "1.0" (or any x.0) in a field whose value is supposed to be an int/long/etc., you get an error. Instead it's best that such integer values be converted to ints (i.e., 1.0 -> 1). 2. If you turn the slider for integer values, it sends non-integral double values (1.23 etc.). I've updated our internal code. Here are the two files I modified to fix things. Let me know if these work for you. sim/util/Properties.java