A library client or storage agent requested a mount of a file volume in a drive that is contained in a file library but the path definition does not contain a matching directory name. There must be a matching directory in the PATH definition for each drive in a file library and the corresponding directories in the device class associated with the library. The directories in the PATH definition must point to the same storage as those of the device class definition, from the perspective of the specific server or storage agent. The list of directories must have entries for each directory in which file volumes are to be read or written by the specified server or storage agent.