Do you have this atrribute on your classes [EPiServerDataStore(AutomaticallyRemapStore=true)]

I believe they made changes between cms6 and cms6 r2 so you probably have to update stuf when upgrading to cms7. Have a look at this blog post from paul smith: http://world.episerver.com/Blogs/Paul-Smith/Dates1/2011/4/Dynamic-Data-Store--Tips-Tricks-and-Best-Practises/

http://world.episerver.com/Blogs/Paul-Smith/Dates1/2011/2/Dynamic-Data-Store--Easier-Store-Creation-and-Remapping/

Thanks for the response, Eric.  I have used this method succesfully before for custom properties that we have built from scratch, but this appears to have something to do with the VisitorGroup store so I cannot add the attribute you have mentioned.

For further clarification, here is the rest of the stack trace:

[InvalidOperationException: 
The property Criteria exists on both the old and new definitions but does not have the same type and is not convertible between the types.]
   EPiServer.Data.Dynamic.StoreDefinition.RemapChanges(IDictionary`2 copyTypeBag, IList`1 newMappings, List`1 dataMoves) +1908
   EPiServer.Data.Dynamic.StoreDefinition.Remap(IDictionary`2 typeBag, StoreDefinitionParameters parameters) +900
   EPiServer.Data.Dynamic.StoreDefinition.Remap(Type type) +76
   EPiServer.Personalization.VisitorGroups.VisitorGroupStore.GetStore() +312
   EPiServer.Personalization.VisitorGroups.<List>d__0.MoveNext() +116
   System.Linq.WhereEnumerableIterator`1.MoveNext() +87
   System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source) +4216372
   EPiServer.Personalization.VisitorGroups.VisitorGroupInitialization.ValidateVisitorGroups(IEnumerable`1 visitorGroups) +177
   EPiServer.Personalization.VisitorGroups.VisitorGroupInitialization.InitializeStoredVisitorGroups(IServiceLocator locator) +135
   EPiServer.Personalization.VisitorGroups.<>c__DisplayClass1.<Initialize>b__0(Object , EventArgs ) +75

Most likely the reason for this is a problem with assembly redirects. Please, check in your web.config:

• there should be only one assemblyBinding element inside configuration/runtime element
• the assemblyBinding element should have namespace defined: xmlns="urn:schemas-microsoft-com:asm.v1"
• assemblyBinding should contain dependentAssembly element with correct bindingRedirect for EPiServer.ApplicationModules assembly (the one that contains type for the Criteria property)

Sergii was right!