Tf400324:team Foundation Services is not available from server ...

Quick Fix

As a quick fix you can

1. Close Visual Studio and related apps
2. Browse to %localappdata%\microsoft\team foundation\4.0\cache and delete all the contents of this folder

This isn ' t ideal as you'll need to does this for each client and every time you switch between the 2.

Better Fix

As a better and more user friendly fix that you can

1. Do the Quick Fix
2. TS to the server where are you having the new TFS server with a copy of your collection attached (my TFS instance)
3. Open a command line window in Administrator mode
4. Run cd C:\Program Files\Microsoft Team Foundation Server 12.0\tools "
5. Run tfsconfig changeserverid/sqlinstance:<your Sql Instance name>/databasename:<your Configuration Database name>/projectcollectionsonly
6. This should bring-a message that says "the command ChangeServerID should" is run against a set of Team Foundati On Server databases This has no application tiers configured. Does want to continue with this operation? (yes/no)"
7. Type Yes and hit Enter

Now you should is fine to use both instances of TFS with the same collection name without issues

Tf400324:team Foundation Services is not available from server ...