Can't delete empty folder

[MichaelDano]

In one of my sites libraries I have an empty subfolder which I can't delete.
When I right click on the folder and choose Delete I get this:

I have no idea to who have made these shortcuts. 

I choose delete and although the folder is empty I get this:

I'm owner of the site and have Admin privileges.

Any ideas on how to get rid of this subfolder?

Thanks in advance!
Michael

[#2]

@MichaelDano 

If you have owner rights try to check in the Library settings for "Manage files which have no checked in version"

As owner you can see if a user left a file without checked in version.

This may be the reason why you are not able to delete the folder

[#3]

@mr_w1nst0n - thanks, but that list was empty (which is coherent with the folder not holding any files).

[#4 · Accepted solution]

@MichaelDano I believe you may have an hidden file inside the folder.

Could you check it via PowerShell ?

Here you have already a PowerShell script as sample: SharePoint Online: PowerShell to List All Files Inventory in a Document Library - SharePoint Diary

[#5]

@mr_w1nst0n - Thanks - you were right.
How do I unhide the files?
Why does this happen in the first place?

[#6]

@MichaelDano there may be multiple reasons for that. Sometimes it depends from the application/OS system you are using.

In my case it was Autocad generating hidden files in the folder (synchronized to SP).

Adobe Photoshop/Lightroom also generate hidden files sometimes

If they are not needed, you can delete the files directly via PowerShell