My PC suddenly did not want to make connections to ftp sites using FileZilla.


What I did:


  1. connected to my phone/hotspot and it works again no problem
  2. connected back to my home network and it does not work anymore
  3. googled my provider (KPN) and ftp issues and found the solution: I had to lower the firewall of my router from medium to low and that works

Conclusion: providers change and update their systems and then suddenly "things" do not work anymore. This is creepy! Call them or do as I did: google the issue...