Has your connectivity to
Visual Studio Online (VSO) from Visual Studio suddenly stopped working or it's giving you trouble? Are you able to log in via the web, just not from VS? If so, this may be
due to a bad cookie or cache. We rely on cookies \ IE for our VS connectivity settings, so you may be able to clear this up by following the steps below.
The goal here is to get this sign in dialog to appear when you initiate a connection from VS to
Visual Studio Online (pictured below). Unless your credentials are stored correctly (cookie)
you will not be able to connect to
Visual Studio Onlinefrom VS unless you see & use this dialog.

NOTE: The steps below apply to all versions of VS, but for VS 2008 & 2010 you also need to do ensure all the necessary updates are installed*. When
in doubt, use Control Panel>Programs & Features to remove the updates and reinstall them if the steps below do not restore your VS 2008\2010 connectivity.
*To connect to VSO VS 2008 you need VS 2008
SP1 and
this GDR.
*To connect to VSO from VS 2010 you need VS 2010
SP1 and
this GDR.
Delete the
Visual Studio Online
cookies
1. Close
all browser instances, Skype, Skype, etc... anything else that is signed in with your Microsoft account (formerly "Live ID").
2. Open Internet Explorer (don’t use InPrivate) and
navigate to https://app.vssps.visualstudio.com/_signout. This will delete live cookies, feadauth tokens for all VSO accounts and also sign you out Azure Active Directory.
3. Use
Internet Explorer to delete all your Temporary Internet File and Cookies. In later versions of IE you can access this dialog by pressing CTRL+SHIFT+DEL. Otherwise it's under Internet Options>General>Browsing History>Delete. Be sure
to delete cookies and uncheck the "Preserve Favorites website data" item.

I’d also suggest manually deleting the contents of these folders using File Explorer (DIR path may be different depending on your OS):
- C:\Users\[YOUR NAME]\AppData\Local\Microsoft\Windows\Temporary Internet Files
- C:\Users\[YOUR NAME]\AppData\Roaming\Microsoft\Windows\Cookies
- C:\Users\[YOUR NAME]\AppData\Local\Microsoft\Windows\INetCookies
Rename the TFS \ VS Cache
1. Close all open instances of Visual Studio (**IMPORTANT**).
2. Run the following from a .CMD in an elevated Command Prompt.
SET AppDataTF=%USERPROFILE%\Local Settings\Application Data\Microsoft\Team Foundation
SET AppDataVS=%APPDATA%\Microsoft\VisualStudio
IF EXIST "%AppDataTF%\2.0\Cache" MOVE "%AppDataTF%\2.0\Cache" "%AppDataTF%\2.0\Cache.OLD"
IF EXIST "%AppDataTF%\3.0\Cache" MOVE "%AppDataTF%\3.0\Cache" "%AppDataTF%\3.0\Cache.OLD"
IF EXIST "%AppDataTF%\4.0\Cache" MOVE "%AppDataTF%\4.0\Cache" "%AppDataTF%\4.0\Cache.OLD"
IF EXIST "%AppDataTF%\5.0\Cache" MOVE "%AppDataTF%\5.0\Cache" "%AppDataTF%\5.0\Cache.OLD"
IF EXIST "%AppDataVS%\9.0\Team Explorer" MOVE "%AppDataVS%\9.0\Team Explorer" "%AppDataVS%\9.0\Team Explorer.OLD"
IF EXIST "%AppDataVS%\10.0\Team Explorer" MOVE "%AppDataVS%\10.0\Team Explorer" "%AppDataVS%\10.0\Team Explorer.OLD"
IF EXIST "%AppDataVS%\11.0\Team Explorer" MOVE "%AppDataVS%\11.0\Team Explorer" "%AppDataVS%\11.0\Team Explorer.OLD"
IF EXIST "%AppDataVS%\12.0\Team Explorer" MOVE "%AppDataVS%\12.0\Team Explorer" "%AppDataVS%\12.0\Team Explorer.OLD"
If after doing all this you are still having issues, try:
1. Resetting Internet Explorer settings to default by opening Internet Options, going to the Advanced tab and clicking the "Reset..." button at the bottom of the dialog.
2. Removing and re-adding the VSO account inside VS using the "Connect to Team Foundation Server" dialog
3. Check the Credential Manager (accessible via Control Panel) for stored Windows creds. You may need to clear these out too as they could override your cookies.
4. Check your proxy settings inside IE. If you can access the Internet without a proxy, disable the proxy as a test. We have seen proxy settings here which prevent the Microsoft account login dialog (pictured at the top of this post) from
appearing.
Trevor Hancock (Microsoft)
Please remember to "Mark As Answer" the replies that help.