Some time ago, I wrote about the release of the March cumulative update for SharePoint 2013.
Note that a new update was released in April! Always available via the same address: http://technet.microsoft.com/en-US/sharepoint/jj891062
Those cumulative seem to be very important in the context of migration! In fact in the description of March corrections, it is said
« Assume that a SharePoint Server 2010 site contains a navigation link that points to an invalid URL. After you upgrade SharePoint Server 2010 to SharePoint Server 2013, you cannot access the site.”
« Assume that you attach a SharePoint Server 2010 content database to a SharePoint Server 2013-based server. In this situation, when you upgrade the site collection on the SharePoint Server 2013-based server, picture libraries are not updated.”
And the April
« When you try to upgrade some site collections from SharePoint Server 2010 to SharePoint Server 2013, you encounter a save conflict error.”
Think about it !