your query has a sum column,

Sum(Nz([UnitsReceived])-Nz([UnitsShrinkage])-Nz([UnitsUsed])-Nz([UnitsSold])+Nz([CycleCountCorrection])-Nz([UnitsOnNCR])) AS QOH



but that only works with aggregate queries - you need to group on all the other fields. Your error message is telling you that. If you removed the lotnum column, you would get the same error message, but this time referring to UnitsOrdered

Not clear whether you are wanting to sum or not (sum adds values from different records, hence the need to group), but remove sum and this error will go away