I too created a new project using Basic Lens, added the instrument track, success, the problem did not occur after save.
Created another new project , imported suspect MIDI file into new project, added instrument track , successfully save and opened
Strange... possibly some file corruptions , will have to test a few more files hopefully its only a few with the issue since I have thousands of MIDI files
Well , thanks for the assistance scook, at least I know I an generate a new project and not get the issue.