Troubleshooting 

Code 

Description 

400 Series  

The command was not accepted and the requested action did not 

take place, but the error condition is temporary and the action may 

be requested again. 

421 

Error 421 Service not available, closing control connection.  

Error 421 User limit reached 

Error 421 You are not authorized to make the connection 

Error 421 Max connections reached 

Error 421 Max connections exceeded 

Possible Solutions 

You can receive that 421 error if the FTP server you are connected to 

limits the total number of connections available or limits the connections 

available to one user.  There are three things you can do: 

1.  Limit the number of connections to any one FTP site by selecting 

Tools > Global Options > Connection and set "Per site max 

connections /transfers" to 1 (By default it will be set to 2). 

2.  Remove items from the Transfer Queue.  The Transfer Queue is 

where you see items ready for transfer, in transit, or just 

transferred.  Sometimes the Queue Pane can become cluttered 

with unfinished transfers.  To clear the queue, right click inside it 

and choose Remove All. 

3.  Make sure only one instance of CuteFTP is running on your 

system.  Open the Windows Task Manager and see if CuteFTP is 

listed more than once. 

425  

Can t open data connection.  Try changing from PASV to PORT mode. Check 

your firewall settings. Try making an HTTP connection. 

426 

Connection closed; transfer aborted. 

450  

Requested file action not taken. File unavailable (e.g., file busy). 

451 

Requested action aborted: local error in processing. 

452 

Requested action not taken. Insufficient storage space in system. 

500 Series  

The command was not accepted and the requested action did not 

take place. 

501  

Syntax error in parameters or arguments. 

502  

Command not implemented. The server does not support this command.

503 

Bad sequence of commands. 

241