Copying files to remote server failed

I am supposed to upload a website file to remote server. However, I kept getting this error 4 - copying files to remote server failed.

I did some testing around. WinSCP had no problem uploading an empty text file. But whenever I uploaded a file with a single byte, THEN I GET THIS ERROR! I cannot upload anything as a result, and it is really getting on my nerve!

How can I fix this problem?

Any help here will be deeply appreciated.

My friend also tried to upload something on FileZilla, to no avail.

I remember the phrase "a complaint is a gift" from a customer service course. I'd like to adapt it: A good error message is a gift. This is an example of an excellent error message, compared to "an unknown error occurred" that you encounter regularly.

However, to receive the gift, you need to read and understand the message. Surprisingly many people get an error, panic, and dump it into one of the help forums without trying to make sense of it. I understand that having to read English text can be intimidating, but nowadays we have online translation services to deal with that.

Here, it stares into your face: "Uploading a file to a full filesystem" and "exceeding a user disk quota" can't be clearer. The messages mean that the filesystem on the server is full, and/or the disk quota of the account to which you upload the file is used up. To solve that problem, whoever has access to the server has to delete some files, add storage space or increase quota.

Or you are trying to create a directory that exists already. To solve that, don't create the directory.

The only message that might be a bit difficult to understand is the second one. I am not sure why that move is not allowed. May I suggest an internet search?