For Tridion 2009 workflow we are using Event Triggers to listen for the event "activity instance is started". Within the code we have a method that gets triggered when this event is triggered.

The code works fine and we can get the this functioning correctly in the lower environments. However when we move into an environment with high traffic we run into the following error randomly and infrequently.

Unable to cast object of type 'System._ComObject' to type 'Tridion.ContentManager.Interop.TDS.TDSEClass'. Tridion.Extension.Utilities.Util.GetTDSE(String identity) at Tridion.Extension.Framework.Workflow.WorkflowEvents.OnActivityInstanceStartPre(ActivityInstance activityInstance) OnActivityInstanceStartPre.1 :: System.InvalidCastException: Unable to cast object of type 'System._ComObject' to type 'Tridion.ContentManager.Interop.TDS.TDSEClass'. at Tridion.Extension.Utilities.Util.GetTDSE(String identity) at Tridion.Extension.Framework.Workflow.WorkflowEvents.OnActivityInstanceStartPre(ActivityInstance activityInstance)

It looks like error seems to happen within the below code.

TDSE result = new TDSEClass() as TDSE; This works most of the time but randomly we get this error.

Does any one know why this might be happening?