Sometimes files has zero bytes on the server after uploading

[kireerik]

When I upload multiple files sometimes a particular file is uploaded to the server with zero bytes. The file can be different from time to time, so not the same file gets uploaded with zero bytes. Usually these files are small.

See related closed issues:
​#1155 Upload successful but zero bytes in file
​#3963 Files upload to zero bytes length
​#4309 Upload of large files completes, but shows zero bytes on server

[Tim Kosse]

Which FTP server software is the server running?

Are there any firewalls or NAT routers sitting between client and server?

[kireerik]

I have a shared hosting account at ​Network Panda with the latest cPanel installed. I think my hosting provider using ​Pure-FTPd.

No, I am directly connecting to the network via a DOCSIS compliant device provided by a local internet service provider using wireless connection.

[Tim Kosse]

If you're using a wireless connection you are almost definitely behind a NAT router.

Are you using plain FTP or FTP over TLS?

[kireerik]

Yes, you are right. Sorry for the wrong answer. (I am less interested in the low level digital technical part.)

I am using plain FTP.

By the way thank you for all your assistance!

[Tim Kosse]

If your server supports it, try using FTP over TLS. While it wouldn't solve the problem, it would detect truncated transfers and FileZilla would automatically resume the transfer.

Have you tried a wired connection yet?

[kireerik]

Sorry I saw the wrong setting field, and I am already using explicit FTP over TLS. Should I set it to "explicit FTP over TLS required". The current setting is "explicit FTP over TLS, if available".

No, I didn't used my laptop with a network cable since years.

[kireerik]

Are you planning to fix this issue?

[Tim Kosse]

There is nothing to fix yet, no cause has been determined.

To rule out your NAT router as cause, please bypass it by plugging your computer directly into your cable modem using an Ethernet cable.

If you have a hybrid modem/router device, put it into bridge mode to disable the routing part.

[kireerik]

Sorry, but this issue persist only sometimes. So I can not test it out this way. Plus others are using the network as well, so this is not a real solution to test this issue.