The cross-platform TFX tool is, among other things, what you use to create new boiler-plate VSIX extensions (to populate with your own information) as well as to upload individual Release Management (vNext) tasks to TFS 2015. Previously, I’ve logged in using a fully-qualified UNC-formatted username (\domain\dustin.oprea) but this started, suddenly, not working for me. I have not applied any noteworthy updates. I did recently have to change my password (per group policy), but that may or may not have affected it.

As my web-based TFS UI indicated that I was logged-in as “DOMAIN\dustin.oprea”, I unsuccessfully tried logging in as that at the command-line. Eventually, I opened up a private session within the browser in order to log-in using that same username but the UI refused to log me out (even though it was a private session, I was always logged-in). I tried clearing web credential in Windows, but, alas, nothing was stored there (if that could’ve even helped).

I also restarted the system just in case there was credentials-related caching in the system, in or outside of TFS’ application pool.

It turns out that now logging-in with a fully-qualified email-account as my username works just fine.

For example:

C:\>tfx login --auth-type basic --service-url http://localhost:8181/tfs/DefaultCollection --username dustin@email.com
TFS Cross Platform Command Line Interface v0.3.20
Copyright Microsoft Corporation
> Password:
Logged in successfully

Thanks, TFS. Do you think you might unify how users are logging-in both at the command-line and in the UI? Maybe?

Thanks to Could Not Connect, Invalid Credentials, Bad Username/ID/Password for drawing my eye to this potential option.