Teamfoundationserver branching not working in any form - tfs

Question

I have tried branching in a very simple sample project and it worked. Now I want to branch a real life project and it is simply not working.
When I try to branch the whole team project, tfs tells ask for a destination. If I choose a new destination it tells me, that the destination does not exist. If I create a new one and point to it, it tells me that the folder already exists.
When I try to branch the team project into a sub-folder within the team project it tells me that this procedure cant be done, fair enough.
But when I try to branch a single project within the team project to another sub-folder it tells me that there was no correct mapping ('keine passende Zuordnung', in German I don't know the exact English error message).
Any help on this is very appreciated. I fail to see, what I do differently here, then I did before in my test project.
Edit: As suggested I post an image of my project structure. The upper folder is my actuall project which I have converted from a teamproject to a branch. The second on is the destination folder which is empty.

Answer 1

When branching a whole team project ($/ProjectName), you either need to use the New Project Wizard to create a new project and specify that it should branch from your current project.
When branching a sub-folder of your team project, that should work, unless a parent of that sub-folder is marked as a branch root, in which case there is no location to branch to.
Any folder that either holds a branch root as a child, or has abranch root as a parent cannot be used to create a new branch:
On the commandline try running tf branches . from the folder that you want to branch (to see if it is part of a branch) and from the folder you want to branch to. If the target folder is already under a branch, you can't branch to it. You might need to use the Convert to Folder option in the Source control explorer to allow branches to be created there.
It looks like you've already created the target folder, and the target folder is already a branch. You haven't described how that came to be, if it's a result from a Branch action on the source folder, then instead of choosing Branch pick Merge instead.
If there is no relationship between the two folders then it won't be pre-populated in the list of possible merge targets. If you're using Visual Studio 2013 you can enter the path manually and TFS will create the relationship by doing a baseless merge. If you're using an older version of Visual Studio you may need to create this relationship from the commandline:
tf merge "$/TeamProject/Machinenzustandsanzeige" "$/teamproject/Machinenzustandsanzeige NC-Prä" /baseless /recursive /collection:{uri}
You can also destroy the target branch that you've created using the commandline and then re-attempt the branch, which should then succeed.
tf destroy "$/teamproject/Machinenzustandsanzeige NC-Prä" /recursive /collection:{uri}
tf branch "$/teamproject/Machinenzustandsanzeige;T" "$/teamproject/Machinenzustandsanzeige NC-Prä" /recursive /collection:{uri}
tf checkin "$/teamproject/Machinenzustandsanzeige NC-Prä" /recursive /collection:{uri}
In case the workspace isn't setup correctly yet you can either do it through the UI using the steps outlined here or from the commandline using:
tf workfold /map "$/teamproject/Machinenzustandsanzeige NC-Prä" c:\path\where\you\want\it
followed by:
tf get "$/teamproject/Machinenzustandsanzeige NC-Prä" /recursive
to effectuate the addition of the folder.
There is a very slim chance that the a-umlaut is causing the issue. Have you tried a path without special characters?
What you want to achieve is a standard operation and TFVC supports it, but somehow you ended up in a situation that is non-default. Even in such a situation you can get it fixed, but you might need to resort to advanced features such as /baseless or /force or tf destroy which are not available from the UI.