Ever got this error while developing SharePoint 2010 Workflows in Visual Studio? System.InvalidOperationException: The event receiver context for Workflow is invalid. at Microsoft.SharePoint.SPEventReceiverDefinition.ValidContext() at Microsoft.SharePoint.SPEventReceiverDefinition.GetSqlCommandToAddEventReceivers(IList`1 erds) at Microsoft.SharePoint.Workflow.SPWinOESubscriptionService.CommitNewSubscriptions(Transaction txn, IList`1 erds) Check the you have set the all the TaskIds in your code: TaskId = Guid.NewGuid(); If this is not the case need to check that your Correlation Tokens are setup correctly.