A bug that may eventually have caused serious problems in the energy balance calculation of the soil surface has been detected and corrected. The bug has been when the soil evaporation and soil temperature of the soil surface is calculated for an numerical solution of the energy balance equation of the soil surface. Switch Evaporation method in the Soil evaporation module was set to Iterative Energy balance. The bug may in some cases been causing crashes and infinite values of the energy balance close for the soils surface. However, the bug may also have been hidden and calculations have been made but with a constant thermal conductivity of the uppermost layer instead of a dynamic calculation of the thermal conductivity. The bug has been in the models for the latest 5 years. Improved results may be obtained for soil temperature simulations by using the updated version that allows for dynamic variability of the uppermost layer thermal conductivity.