SharePoint feature activation problem.

If you are one of those who are having problems with feature activation even when you made sure that the dll is in the GAC and everything is looks good while SharePoint gives the following error:

Failed to create feature receiver object from assembly "xyzzyFeatureReceiver_0", type "Conchango.xyzzyFeatureReceiver" for feature b2cb42e3-4f0a-4380-aaba-1ef9cd526f20: System.ArgumentNullException: Value cannot be null.
Parameter name: type
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.Activator.CreateInstance(Type type)
at Microsoft.SharePoint.Administration.SPFeatureDefinition.get_ReceiverObject()

In my case the feature activation works fine in the Test environment but not on the Dev Environment.

I don't think its a true statement: "Your feature and it's feature receiver must have the same root namespace or the solution will not deploy."

In my application design, I have a feature receiver and the feature in separate namespaces and it still works.

Solution: It worked when I use the -force option while activating the feature.

STSADM -o activatefeature -n Quintiles.SDMConfigChanges -url http://entportdlb.inet.quintiles.com/SDMMapping -force