I get a dialog box prompting for a date:

I am wondering if it has to do with WHERE below:
Final Date Query
SELECT [StartEnd-CONV Query].[Employee File Number and Name], [StartEnd-CONV Query].PTOTaken, [StartEnd-CONV Query].Adjustments, [Specific Date-CONV Query].[Company Code], [Specific Date-CONV Query].[BBF Accrued Hrs], [Specific Date-CONV Query].[Separation Date], [Specific Date-CONV Query].EarnedHrsAvail, [Specific Date-CONV Query].[Rehire Date]
FROM [StartEnd-CONV Query] INNER JOIN [Specific Date-CONV Query] ON [StartEnd-CONV Query].[Employee File Number and Name] = [Specific Date-CONV Query].[Employee File Number]
WHERE ((([Specific Date-CONV Query].[Separation Date])>=[Date] Or ([Specific Date-CONV Query].[Separation Date]) Is Null)) Or ((([Specific Date-CONV Query].[Rehire Date])>=[Separation Date]) And ((Forms![StartEnd-CONV]!txtEnd)<>False))
ORDER BY [StartEnd-CONV Query].[Employee File Number and Name];
But when I tried this:
WHERE ((([Specific Date-CONV Query].[Separation Date])>=[StartEnd-CONV Query].[txtEnd] Or ([Specific Date-CONV Query].[Separation Date]) Is Null)) Or ((([Specific Date-CONV Query].[Rehire Date])>=[Separation Date]) And ((Forms![StartEnd-CONV]!txtEnd)<>False)).
it ends up with a prompt for a Date and a 2nd prompt for [StartEnd-CONV Query].[txtEnd]
So now I am unsure where the issue resides.