访问查询 - 要评估的太复杂，数值表达式可能包含太多复杂的元素

I have an access database. There is a field that is [Start Date]. The [Start Date] has values of 01/01/2017 and only one that is 07/24/2017. The [Start Date] field is a Short Date field in the table. When I change the 7/24/2017 to 01/01/2017 the query runs fine, however when I have July selected in the drop down and that form value is 7 and the 2017 in the Year drop down the following query says it is too complex to be evaluated. I am trying to use the dateserial function to do a datediff and some division against a value with a decimal. Here is the query:I have an access database. There is a field tha