The following is a list of breaking changes in EPiServer CMS 5 R2.
EPiServer.Web.Hosting.NativeFileSummary.SaveChanges() will now throw an exception.
This means that calling UnifiedFile.Summary.SaveChanges() will throw an exception if the backing Virtual Path Provider is an EPiServer.Web.Hosting.VirtualPathNativeProvider (or another provider which does not support storing of file summaries).
Check IUnifiedSummary.CanPersist before saving changes to the summary.
New file structure
The new installation procedure for EPiServer CMS 5 R2 will change the file structure of the Web site.
Consequences for Web sites based on the Demo Package R1
Note that changes has been made to the platform that may affect Web sites that are based on Demo Package R1.