Did you find anything in the logs (/var/log/vmware/applmgmt)
And is FTP server backed by Winows or Linux based OS?
How is the FTP server setup?
Also please check the logs:
1. Using putty or similar, SSH in as root on the appliance.
2. Type Shell at the prompt.
3. Type cd /var/log/vmware/applmgmt.
4. Type more backup.log or tail backup.log.
I think the job did finish (see last line in log file) but it actually tried to make the files READ ONLY and failed.
Can you verify if there are files present in the FTP folder?
There Backup files already store to the FTP server.
But，the backup progress all the time stop at 0%.
I had the same strange issue using an older browser (Internet Explorer 11) from a Windows 2008 R2 server we use for maintenance purposes. The backup progress update communication is somehow broken in older browsers.
Try a newer browser like Google Chrome to connect to VCSA management - that worked for me.
using Chrome browser is OK.