Windows Security blocks FileZilla installation
I got this error in german, it vagely stated, I could not open the installer because the file possibly contains undesired software or a virus.
Indeed it did. The prominent download link on filezilla-project.org lets you download a file called something like "FileZilla_3.59.0_win64_sponsored2-setup.exe". This contains adware. Not cool.
With the link "Show additional download options" you get access to the clean downloads.