Please use the system settings 
to setup the connection to your FTP-servers. Here you find help when the connection fails.
The FTP Client keeps the last connection you used and opens it with the program. If you used a connection already but suddenly Tool&Task say 'not connected..'
it is in most cases not the fault of this FTP client. Check (perhaps by calling the administrator or opening a remote terminal), if the FTP-service is actually running on the respective server. Check if the user and password you use is still valid. Check whether your internet connection is ok by opening any homepage. Check whether you are running a VPN at the moment and this impairs the FTP access.
If this is all ok, tell us, Tool&Task was not connecting properly.