Problem with ungrib

I am trying to use the 3 preprocessors within the Domain Wizard. I have no problem with geogrid but there is trouble with ungrib. The message after executing is:
ungrib.exe: error while loading shared libraries: libpng16.so.16: cannot
open shared object file: No such file or directory
ungrib.exe FATAL ERROR exitCode=127
Then it also states that it could be due to a date mismatch between
namelist.wps and GRIBFILE.AAA, but I checked that there is no such disagreement.
Finally, I am able to run ungrib if I do it directly (outside the Domain Wizard). This fact proves that libraries are correctly installed and linked. Does anyone have an answer for this Domain Wizard problem ?
ungrib.exe: error while loading shared libraries: libpng16.so.16: cannot
open shared object file: No such file or directory
ungrib.exe FATAL ERROR exitCode=127
Then it also states that it could be due to a date mismatch between
namelist.wps and GRIBFILE.AAA, but I checked that there is no such disagreement.
Finally, I am able to run ungrib if I do it directly (outside the Domain Wizard). This fact proves that libraries are correctly installed and linked. Does anyone have an answer for this Domain Wizard problem ?