TL;DR; Explains the TF14002 error in TeamPlain, where NT AUTHORITY\NETWORK SERVICE lacks valid user group access, and discusses possible causes like proxy server settings.

Some prople have encountered this error when viewing the source control tab in TeamPlain:
System.Web.Services.Protocols.SoapException: TF14002: The identity NT AUTHORITYNETWORK SERVICE is not a member of the Team Foundation Valid Users group.
at Microsoft. TeamFoundation. VersionControl. Server. Repository. GetRepositoryProperties()
Now in the TeamPlain forums a couple of posts defign the problem, but no solution:
SoapException with Source tab posted 03-27-2007 4:39 AM
TF14002: The identity NT AUTHORITYNETWORK SERVICE is not a member of the Team Foundation Valid Users group. posted 05-17-2006, 4:31 AM
1.1 Problems posted 10-14-2006, 12:37 AM
It seams that this is an internitant problem and may be caused by proxy server settings.
This has only hapened to one of my users sos far and not to me at all.
We will see…
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