Command retrlines timed out

[f43310]

All of a sudden, FTPSync stopped to work.
Here's my console output:

b'FTPSync > Loading config: cache hit (key: D:\websites\rainknow)'
b'FTPSync [default] > Connected to: 39...*:21 (timeout: 30) (key: None)'
b'FTPSync [default] > Logged in as: web (using password: YES)'
FTPSync > Command retrlines timed out, retrying (4 remaining)...
FTPSync > Command retrlines timed out, retrying (3 remaining)...

And here's my config file:
`"default": {

	"host": "39.*.*.*",
	"username": "w*****",  // or null for anonymous login
	"password": "******",
	"path": "/rainknow.******.com/",

	"upload_on_save": true, // set *false* if you do not want to upload on save!

	// "port": 21,
	// "tls": false,
	// "timeout": 30, // [seconds]

	"passive": false,

}`

I tested the connection through WinSCP and it works.
I tested the connection through SFTP(sublime text3 package) and it works.

I'd really appreciate any help!