When WordPress files are FTP uploaded to the server via FileZilla Client, some files (such as ‘wp-admin/includes/ms.php’) are only partially uploaded and not entirely and hence not properly uploaded.
Due to this error in uploading, FileZilla FTP retries to upload the same file again and again resulting in another error mentioned on page Filezilla FTP Error: 421 Too many connections (8) from this IP.
The only solution known till now is to change the overall method of uploading WordPress files to the server.
cPanel (or corresponding utility) should be used to upload files instead of FileZilla FTP Client.
Following steps should be executed:
- Compress all the source code files into an archive. (.zip and not .rar)
- Login into cPanel.
- Click on link called ‘File Manager’.
- Upload the archive using functionality provided by ‘File Manager’.
- Extract the contents of archive at desired location.
Thus files will be uploaded on the server.