It is not possible to run the installer until the file is allowed by an administrator of the system by loading Windows Security from Start, selecting the App:FileZilla_BundleInstaller threat under Virus & Threat protection, and setting it to 'allow on device'. The threat 'App:FileZilla_BundleInstaller' is listed with a low severity rating when the file has been scanned by Defender. If you download the client anyway using that option, you may get a Windows Defender warning about potentially unwanted software.

Text on the page highlights this: 'This installer may include bundled offers.

The main download page offers a download for Windows only this particular version includes a bundled offer, aka adware. The maintainers of the application have released FileZilla Pro, a commercial version with features that add support for WebDAV and several file storage services such as Google Drive, Box, Dropbox, and Microsoft OneDrive. The application was selected for the European Union's bug bounty program among other software applications.

Filezilla pro for mac