I’ve been knocking my head and waiting for a very longest time for my turn to upload my files to server (because of my colleague is uploading large files to the server). While waiting to that, I was murmuring so hard, I spelling out maybe she can upload using cPanel while waiting for couple of minutes or hours. On the otherside, Maybe I can do as well. Atleast I can do my job done.
anyways.. Here is a instruction how to resolve your issue with your filezilla connection issue.
1. Go to File
2. Choose Site Manager
3. Select Transfer Setting tab
4. Check/Tick the “Limit number of simultaneous connections”
5. Set the “Maximum number of connections” to 1
Sometimes if you did the settings and still encounter the same issue. I suggest to restart your router so that it will completely shut off all the connection.
Alternative solution to fix the error 421, If you have an access to you cPanel account.
Go to you cPanel Account
Then you can eliminate any ftp connection connected.