If a unit from the unit of measure table and a corresponding unit conversion is removed from D365, a warning message appears next time Planning optimization is executed, saying “Could not find unit of measure with id ********”. That does only happen if the unit and unit conversion we're processed before in at least one Planning optimization run. This warning message can cause confusion, as the missing unit of measure is no longer used. Planning optimization should therefore only process those units of measure and unit conversions that still actually exist in the unit of measuretable.