Kiva, wallfilm problems
 

I am trying to run engine simulation. After injection, as soon as a spray droplet reachs the wall, the calculation stops and I obtain the message: sie driven negative in subroutine pcoupl, ncyc= 1609 crank= -1.06 i4= 6501 sie= NaN temp= 2.61860E+03

When I follow it throw the code I find that the problem is in the routine wallfilm, where dsiep becomes a NaN. How can I cure the problem?