We have a long standing issue in our bug tracking system about the dreaded "ERROR: request not found in the TrackedRequests. We might be creating and closing webs on different threads." message in SharePoint's trace log.

As we develop Workflow software for the SharePoint market, we look into this issue from time to time to make sure it is not caused by our products. I have personally come to the conclusion that this is a problem in SharePoint, but perhaps someone else can prove me wrong.

Here is what I know:

1. According to the hundreds of search results returned by Google on this topic, this issue appears to be mainly related to SharePoint Workflows, both SharePoint Designer and Visual Studio based workflows.

2. Assuming ULS logging is set to Monitorable, the easiest way to reproduce this problem is to create a new SharePoint Designer Workflow, attach it to a document library, set it to auto start on add/update, don't add any actions, save the workflow and upload a file to the document library.

3. The error is only visible in the SharePoint trace log, it does not appear to impact the execution of the workflow at hand.

4. I have verified that the problem occurs on 32 bit as well as 64 bit systems, Win2K3 and 2K8, WSS and MOSS with SharePoint versions up to the December 2009 Cumulative Update (6524).

5. The problem does not occur when a workflow is started manually.

6. There are dozens of related posts on MSDN Forums, hundreds on Google, one on StackOverflow and none on SharePoint Overflow. There appears to be no answer.

Does anyone have any idea about what is going on, what is causing this and if we should worry or file this under 'Red Herrings'.