Whenever I tried to update or create templates from the AMS, I received an error message saying "Unable to upload '/tmp/xxxxxx' file" or "upload failed".

This could be due to a few possible reasons:

1. File permission at the Publisher's "[docroot]/templates/" path has been changed where the website user does no longer has permission to 'write'. You have to contact your system admin to check the file permission whether it still belongs to the website user.
2. The Publisher's diskspace, where NeoFission MX sits, might already be full. This will prevent any file or template from being updated or created. In such an event, you need to clear some diskspace or add more disk to increase the space for the application.
3. Check that the proFTPD daemon at the Publisher is running by performing a manual FTP process from the AMS to the Publisher in question. If you can't FTP from the AMS to the Publisher, then you have to restart the proFTPD daemon at the Publisher by issuing a command: killall -9 proftpd /usr/local/mxae/sbin/proftpd -c /usr/local/mxae/etc/proftpd.conf