Why I can't remove "LibreOffice-BreezeDark-master.zip"? How can I uninstall it?

It looks like a result of a wrong installation procedure (you must unpack the extension file prior to attempting to install). I could not find any other way than deleting everything from the uno_packages subdirectory in the user profile and reinstalling necessary extensions.

@gabix LO should let user uninstall it somewho. This represents LO weakness.