Please I am trying to create Temperature dependent viscosity model on OpenFoam4. When I compile wmake libso commande, I get a message error saying:

ld -r -o /home/mars/OpenFOAM/root-4.1/platforms/linux64GccDPInt32Opt/lib/libusertempdeppowerLaw .o Make/linux64GccDPInt32Opt/tempdeppowerLaw.o
ld: ne peut pas trouver .o: Aucun fichier ou dossier de ce type
make: *** [/home/mars/OpenFOAM/root-4.1/platforms/linux64GccDPInt32Opt/lib/libusertempdeppowerLaw] Erreur 1


Any help please
Thank you