A model with both mass and qt streams is working very well, but a model with only mass streams is not working.

To solve this error I modify the "checking" condition (check {ly in HeatCascades, lc in LocationsOfLayer[ly]: card(StreamsOfLayer[ly]) > 0}: card(HC_Cold_loc[ly,lc]) > 0;) in *.mod files.
I also update Graph.Lua and gnuplotHelper.lua.