Found some more breaking changes:

System.Web.Personalization no longer exists. I believe it’s been renamed to System.Web.Profile but I haven’t 100% confirmed this yet.

System.Configuration.Settings no longer exists. I can’t find its replacement. I’m looking for where IProvider and ISettingsProvider are defined now. I can’t find these either, so I’m thinking they may no longer exist.

I’m not sure if it’s new or not, but I hadn’t seen System.Data.ProviderBase before, so perhaps that’s where some of this functionality has moved.

Looks like these two Interfaces are no longer used, and instead it’s using a base type System.Web.Profile.ProfileProvider which is derived from System.Configuration.SettingsProvider. I had written a custom provider for the personalization engine that used an XML file in the /Data folder for its data. Looks like I’ll need to modify that class quite a bit to conform to this new pattern for providers.