Duplicated folders in github

Git is case-sensitive, but Windows is not. So, the two directories aren't duplicates in Git's view.

If you renamed TulpepWebsite to TulpepWebSite sometime in the past, then all the files which were under TulpepWebsite would have been tracked by git under that old name, while any new files you added would be tracked under the new name.

To fix this, I'd just git-mv the folder to something else, commit, then git-mv it back to the old name and commit again. This will hopefully force all of the paths to use a consistent case.

They arent duplicates: TulpepWebsite and TulpepWebSite (note the capital S).

You probably renamed the folder and git may have not removed the now non-existent folder... check this with git status, and then manually remove the folder from git by running git rm TulpepWebsite/