SYMPTOM:
When attempting to republish a cube that was created by uploading a file using Data Import, with a file that is a different format, for instance *.xls vs. *.csv, the error below occurs in Strategy Web 9.4.1:

Get Results failed: (Changing the Import Data source type is not supported.Error in Process method of Component: QueryEngineServer, Project Strategy Tutorial, Job 75, Error Code= -2147212140.)