Sitefinity 5.1 Won't delete module

In SF5.1 I browse to Administration > Modules then I scroll down to a dummy module that I created and click Actions > Delete. SF shows a confirmation box with the following description: "Delete this module from the list of uninstalled modules", which doesn't make sense at all. Are we deleting it or not?

Then I click ok, SF goes back and does something, comes back and would you know it, the module is still there.

Why?

I have this problem too using Sitefinity 5.4 and using the sample Locations module.

This proved useful

www.sitefinity.com/.../module-install-and-uninstall-issues