>>

>>;with cte as (select cast(Version.[Date] as Date) as [DateNoTime], *, 
>>COUNT(*) OVER (partition by cast(Version.[Date] as Date)) as cntVersionsPerDay, 
>>row_number() over (partition by cast(Version.[Date] as Date) ORDER BY Version.[Date] DESC) as Rn
>> from dbo.Version)
>>
>>insert into VersionProduction (AddUser, AddDate, ....)
>>
>>select ....
>>
>>from cte where Rn = 1

>
>But, what is updating Version.NoVersionProduction in there?

It is part of the select columns list, in other words, you're selecting the PK from your version table using the above technique.