
ProUnitModifyByExpressionAndType | |
( ProUnititem* unit /* (In) The unit. */ ProUnitType type /* (In) unit type. */ ProPath expression /* (In) The unit expression. */ ) |

The function succeeded. | |
One or more arguments was invalid. | |
The unit cannot be modified because it is referenced from the principal system of units or it is referenced from ref_unit. |

