the problem is probably his/her firewall, try switching it off to see if it helps. its not a good long term solution but will diagnose the problem. if you are using IE try using Passive FTP, (see the advanced tab in Internet Options)
Microsoft Surface Book 2 15in review
How to create explosive dance music graphics
The best backup software for Mac 2018
iOS 12 : comment créer et modifier des Memoji ?