Warning displayed when adding solution to Team Foundation Server 2010

I'm just getting to grips with TFS 2010 (never had any luck with TFS 2008) and I'm trying to add my first solution into TFS. However I am getting the following warning message:

The project that you are attempting to add to source control may cause other source control users to have difficulty opening this solution or getting newer versions of it. To avoid this problem, add the project from a location below the binding root of the other source controlled projects in the solution.

Can someone explain to me what this means and how to resolve it? This warning is displayed when right clicking on the solution in Solution Explorer and selecting "Add to Source Control".

Your solution folder structure should resemble:

Solution Root folder
├── .sln solution file       
│
├── Project1 folder
│   └── Project1.csproj   (or .vbproj)
│
├── Project2 folder
│   └── Project2.csproj   (or .vbproj)
.
.
.

As described in this Visual Studio forum post (link below), the basic issue is that a project in the solution is outside of the sub-tree that the solution itself is in. This can possibly lead to problems if another user maps the different subtrees differently in his workspaces than the user that is checking in. The cross-tree references will no longer work. The dialog is only a warning, but can be continued if you know your team doesn't split up the code tree with complex workspace mappings.

https://social.msdn.microsoft.com/Forums/vstudio/en-US/29579a28-9de0-4fc6-a253-b38191aa4fdc/must-projects-be-added-under-binding-root-of-solution?forum=tfsversioncontrol

For me it was like this that I tried to add the solution from another location already. I then had to clean the workspace which was created for the other location.

For Visual Studio 2013 you can find the workspace settings under:

File -> Source Control -> Advanced -> Workspaces...

1. On the Manage Workspaces dialog select your workspace you work with
2. Hit Edit....
3. On the Edit Workspace <yourworkspacename> dialog
4. clear the "wrong" location

Try to add the solution again.