Cannot delete / re-install sharethis module I upgraded my Drupal to the latest version. I also did this with the modules. When I was doing this I got an error for the "sharethis" module. I got a message that told me to upgrade that module myself, so I uploaded the new module files.

But the module isn't working anymore, and when I look at the module-list I cannot find "sharethis".

This is what I see:
ShareThis Block   7.x-2.2   This module creates a custom block for the ShareThis widget.
Vereist: Sharethis (MISSING)

When trying to reinstall the module I get this message:
"Sharethis is aleady installed"

So I can't uninstall/install this module! Also when deleting the directory it gives the same error. (already installed) So I want to delete and re-install a module that's not visible in the module-list.
I had the same problem previously, turns out I had copied the module inside itself.
Duplicating modules inside modules directory might give this error.