If you can connect to a remote server in FileZilla/FileZilla Pro using FTP or FTP with TLS, but not see remote directory listings or transfer files, there is probably something between your client o and the remote server that is interfering with the connection. Generally this will be a virus scanner, firewall, or NAT router.
Use FTP Test at https://ftptest.net/ to find out where in the connection the problem lies.
If the test connection fails, the problem is on the remote end – talk to your system administrator or hosting provider for assistance.
If the test connection succeeds, then the problem is probably on your local computer or network. Some steps that you can take to diagnose the problem are:
- Check your local computer’s antivirus software. Its settings, list of blocked applications, or logs might show that it has blocked FTP commands from FileZilla Pro.
- Check your local computer’s firewall, if one is enabled. Most modern Windows machines have a native firewall enabled by default; open Windows Defender Security Center (Windows 10) and click on Firewall & network protection to check firewall settings or to configure the firewall to let FileZilla/FileZilla Pro access remote servers.
- Are you using active-mode FTP? (see Active vs Passive Mode) If so, you may need to configure the NAT router to allow it. See FTP Active Mode Configuration for instructions, or go to https://wiki.filezillaproject.org/Network_Configuration for a more indepth discussion of network configuration.
- Is your internet service provider blocking FTP transfers using an ISP-level firewall or NAT router? If so, your only option might be to switch to a different ISP.