What did you set for parameters?
Preset = 0
Parent Object = Kepler-452
Barycenter? = 0
Type Of Object = 1
Binary Moons are Dwarf Moons? = 0
Number of Objects = 60
Name for Group of Objects = S
Minimum Radius in AU or KM = 0.47
Maximum Radius in AU or KM = 0.61
Minimum Radius of Objects in km = 0.2
Maximum Radius of Objects in km = 40
Maximum Orbit Eccentricity = 0.1
Minimum Orbit Eccentricity = 0.0
Inclination to Reference = 94
Maximum Variation of Inclination (degrees) = 11
Ascending Node (degrees) = 0
RefPlane = Extrasolar
Epoch = (Default)
Output File Name = Kepler-452AsterBelt
Whenever I hit Enter, it just crashes. I have a feeling it might be that I didn't put a unit for Semimajor Axis, but it says that you have to do something to make it into kilometers.