SharePoint Designer Server error: There is no Web named " ".

This issue happens if you try to remove FP2000 Extensions from a Virtual Directory from the IIS server

discovered in IIS 5.0 XP version.
I experienced this issue with one directory, while all the others worked just fine. The strange part was that I was able to open the subdirectories of the failing directory. With this in mind, I made a new directory and began copying separate files to the new folder. After a few files, I tried to open it with SharePoint Designer and this was always succesfull. When I copied one of the last folders - which was a hidden folder - I got the error again! From that moment I knew what the cause of the problem was.
When using SharePoint Designer to open a site directly from it's directory (like E:\site\ ) via the "Open Site" button, it is possible to receive the above error.

Solution to solve the error:

It is the hidden folder "_vti_pvt".

Delete the folder and all its contents everything will open like it should.

Issues might arise with FP extensions if files were in the folder but you should be able to recreate it if needed