Inconvenient Test-SPContentDatabase warnings

Last week I installed August 2015 CU on our SharePoint 2013 farm. During the first PSCONFIG I noticed more warnings then usual (or I was dreaming the last time). In the log file I read the following message, one for each content database:

The [<name>] web application is configured with claims authentication mode however the content database you are trying to attach is intended to be used against a windows classic authentication mode.

Where did that come from? Every web application is claims based.

On the internet I found this article Test-SPContentDatabase Classic to Claims Conversion by Trevor Seward. Although I was not (yet) interested in any solution, but wanted to know why, I used that SQL statement to get an answer. Hopefully.

In SQL Server Management Studio I ran the query on a content database:

SELECT TOP 1 [tp_SiteID],[tp_Login] FROM [UserInfo] WITH (NOLOCK) WHERE tp_IsActive = 1 AND tp_SiteAdmin = 1 AND tp_Deleted = 0 and tp_Login not LIKE 'i:%'

The result was:


There you have it. It looks like claims, don’t you think? We use an Active Directory group for SharePoint Support. That AD group is added to the Site Collection Administrators. And the claims format for AD groups is…. right: “c:0+.w|<SID>”

Guess I have to ignore those kind of warnings now. A bit annoying if you tell me.