The current solution has projects that are located outside the solution folder.These projects will not be source controlled in Git repository.To add all the projects to a single Git repository please consolidate all projects under a single folder in AX 7/ D365 F&O

I got the below error while trying to add the project to source control.

The current solution has projects that are located outside the solution folder.These projects will not be source controlled in Git repository.To add all the projects to a single Git repository please consolidate all projects under a single folder. 

Solution:

Simply need to remove three files from the project UNC Path.

Navigate to your solution's UNC Path.

Example: C:\Users\Your User Name\Documents\Visual Studio 2015\Projects

Then permanently delete ("SHIFT + DEL") the .git* files and folder. There are two files and one folder, which may be hidden so ensure you have your folders and search options > View > show hidden files, folder, and drives (Radio Button) Selected.

The files to permanently delete are:

.gitignore (file)

.gitattributes (file)

.git (folder)

Reopen Visual Studio and there is no more relationship to the Git Source Control.

@Rahul