If your FTP program had no issues connecting with your FTP server and today it doesn’t work. There maybe a minor fix. If everything was working yesterday and the error message “Failed to retrieve directory listing” began appearing today then there are 2 possible explanations.
FTP software got updated
The first possible explanation is your FTP server software or your FTP program (FTP client) got updated. The configuration and settings may of been modified without your knowledge. Check to see if your FTP program has recently been updated. If the software has been updated then take a look over the settings to make sure they haven’t changed.
After you have looked over your FTP client program settings. You should look at your server log or look at the FTP server program to make sure there were no changes to your FTP server configurations. If there were any changes then those new settings may be contributing to your issues.
Firewall and IP addresses
If after you have looked over the FTP program’s setting and verify everything is in working order, and have looked at your FTP server software, and there are no issues then you should look at your firewall settings. If you use any hardware or software firewall and you are using a different IP address than one you may of whitelisted then your may get some issues when trying to retrieve the directory listing.
You should also look at your firewall configurations and examine to see if any software updates have occurred recently. If there were any updates then any changes in the configuration may be the cause of your FTP timeouts and the “Failed to retrieve directory listing” error message.
Look at your FTP server logs to find the cause
If you have access to your FTP server logs then you should examine them. The log will show what the issue is that is causing all your troubles. You should jump to latest entries and not look at the older ones. The latest entries in your logs will show what errors are happening when you attempt to connect.