Usually, this error is the result of the remote server or some other piece of network equipment forcibly closing or resetting the connection. This error is not caused by CuteFTP.
Some possible causes are:
The remote server was stopped or restarted.
The remote network interface is disabled for some reason.
There are too many users logged on to the server.
Your account on the remote server is restricted for some reason.
In such situations, retry your connection again later or contact the remote server administrator.
In some cases, this error may also be the result of a firewall or network configuration issue. If you encounter this error when attempting a transfer using PASV mode, try the transfer using PORT mode instead.
To make the switch from PASV mode to PORT mode in CuteFTP Home, open the Site Manager and click once on the the name of the problem site on the left side of the window. On the Type tab change the Data Connection Type to Use Port.
If using CuteFTP Professional, in the Site Manager, right-click on the name of the problem site and click Site Properties. On the Type tab, change the Data Connection Type to Use Port.
In some other cases, the remote FTP server may have difficulty dealing with some of the more advanced capabilities used by the default configuration of CuteFTP Professional. In such situations, configuring CuteFTP Professional so that only one file at a time is transferred, may help.
Some possible causes are:
The remote server was stopped or restarted.
The remote network interface is disabled for some reason.
There are too many users logged on to the server.
Your account on the remote server is restricted for some reason.
In such situations, retry your connection again later or contact the remote server administrator.
In some cases, this error may also be the result of a firewall or network configuration issue. If you encounter this error when attempting a transfer using PASV mode, try the transfer using PORT mode instead.
To make the switch from PASV mode to PORT mode in CuteFTP Home, open the Site Manager and click once on the the name of the problem site on the left side of the window. On the Type tab change the Data Connection Type to Use Port.
If using CuteFTP Professional, in the Site Manager, right-click on the name of the problem site and click Site Properties. On the Type tab, change the Data Connection Type to Use Port.
In some other cases, the remote FTP server may have difficulty dealing with some of the more advanced capabilities used by the default configuration of CuteFTP Professional. In such situations, configuring CuteFTP Professional so that only one file at a time is transferred, may help.