Problem converting simple urdf file in collada

Hi all, I have a problem converting a very simple urdf file in collada (.dae) to use ikfast. I have a more complicated robot but I started to have this error even with a very simple urdf file: I/O error : No such file or directory I/O error : No such file or directory error : xmlNewTextWriterFilename : cannot open uri Document successfully written to prova.dae but the prova.dae file does not exist. The prova.urdf file that I am trying to convert is: so just pure kinematics. I am using ros indigo with openrave compiled from source (latest_stable branch). I am using the command: rosrun collada_urdf urdf_to_collada prova.urdf prova.dae in the same folder of the urdf file. My machine is running Ubuntu 14.04. thanks for your help!