Quote from OakayamGetting this error with waddu 6.4 trying to download from wowinterface:
Object reference not set to an instance of an object.
at Waddu.Core.WorkItems.WorkItemAddonUpdate.DoWork(WorkerThread workerThread)
at Waddu.Core.WorkerThread.ThreadProc(Object param)
I seem to be able to download from wowinterface fine with no errors at all. My guess is a problem with the addon your downloading.