During the installation and set-up of a sound card or controller system, drivers may not be installed for all of the 16 channels. Some installation software will install sound drivers in all 16 channels, some will install only channels zero through 10, some will install only channels 13 through 15. Installing the sound drivers for all of the 16 MIDI mapper channels will usually solve the problem. Alternatively, you can edit the MIDI file to direct the output from a channel without a sound driver, to one of the channels which does have a sound driver installed. The symptom I personally encounter is that the file won't load into the playback program.
Error messages vary.
As yet, I know of no easy fix.