DLL

I have been using an Abaqus dll created using a user-defined routine. Things work well on a serial case. The issue comes when I try to use it in parallel. I am trying to do this on windows 7. The error I get is

forrtl: severe (59): list-directed I/O syntax error, unit 12,

in Fortran I/O but I do not get this error when I run the simulation serially. Any ideas will be helpful.

Thanks