ERROR [+2226] ReEstimateModel: No Usable Training Examples

$./scripts/model_gen.scr     lists/phone_list

ERROR [+2226]  ReEstimateModel: No Usable Training Examples
 FATAL ERROR - Terminating program HRest

Solution: only few phonemes causes problem.

            Open lists/phone_list
              remove some phones from it and try command,  so that you can find which phone causes problem