OK, so I added a field to Activity and History on the LAN side.
Updated the Activity Support Entity properties to include the field as a property.
When SLX goes and gets the 'Activity' object, I guess the 'class' doesn't include this new property....
So if I go
Activity.FieldName = "whatever";
I don't have the correct class code to put the data into the Activity property....which gives me this error:

e:\MyWebSites\NRC5001\SlxClient\SmartParts\Activity\ActivityDetails.ascx.cs(370): error CS1061: 'Sage.SalesLogix.Activity.Activity' does not contain a definition for 'ProductLine' and no extension method 'ProductLine' accepting a first argument of type 'Sage.SalesLogix.Activity.Activity' could be found (are you missing a using directive or an assembly reference?)

So where do I add this Property into the C# .Net code .cs Activity Class files?

Thanks!

Hi RJ,

If you look under the "SalesLogix Activity Support" package then you'll see the Activity entity. You can update the entity to add your additional properties. Same process, you just find the entity under a different package.

Found it, Thanks Ryan!