425 Unable to build data connection

[romanzipp]

Since today I always get a 425 Error when trying to sync files. As FTP Server I am using ProFTPD

FTPSync Log

b'FTPSync [default] > Connected to: <HOST>:<PORT> (timeout: 30) (key: <KEY>)'
b'FTPSync [default] > Authentication processed'
b'FTPSync [default] > Logged in as: <USER> (using password: YES)'
FTPSync > Command storbinary timed out, retrying (4 remaining)...
b'FTPSync [default] > Upload failed: {_controller\\99-backend.php} [Exception: 425 Unable to build data connection: Operation not permitted]'
FTPSync > Exception in user code:
------------------------------------------------------------
Traceback (most recent call last):
  File "FTPSync in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 1421, in action
  File "ftpsyncwrapper in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 467, in put
  File "ftpsyncwrapper in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 949, in __execute
  File "ftpsyncwrapper in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 430, in action
  File "ftpsyncwrapper in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 290, in retryingCommand
  File "ftpsyncwrapper in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 284, in call
  File "lib3.ftplib in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 808, in storbinary
  File "lib3.ftplib in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 274, in voidcmd
  File "lib3.ftplib in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 248, in voidresp
  File "lib3.ftplib in C:\Users\roman\AppData\Roaming\Sublime Text 3\Installed Packages\FTPSync.sublime-package", line 241, in getresp
FTPSync.lib3.ftplib.error_temp: 425 Unable to build data connection: Operation not permitted
------------------------------------------------------------

FTPSync Config

{
    "project_defaults_name": "default",
    "project_defaults": {

        "host": "<HOST>",
        "username": "<USER>",
        "password": "<PASSWORD>",
        "private_key": null,
        "private_key_pass": null,
        "path": "/var/www",

        "encoding": "auto",
        "tls": true,
        "passive": true,
        "use_tempfile": true,
        "upload_on_save": false,
        "port": 21,
        "timeout": 30,
        "ignore": null,
        "overwrite_newer_prevention": false,
        "download_on_open": false,
        "upload_delay": 0,
        "default_folder_permissions": "755",
        "default_local_permissions": "auto",
        "default_upload_permissions": null,
        "always_sync_local_permissions": false,
        "time_offset": 0,
        "set_remote_lastmodified": true,
        "after_save_watch": null,
        "debug_extras": {
            "print_list_result": false,
            "dump_config_load": true,
            "print_ensure_folders": false,
            "debug_remote_paths": false,
            "after_save_watch": false,
            "debug_get_local_path": false,
            "debug_mfmt": true,
            "debug_put_error": true
        }
    }
}

ProFTPD TLS

<IfModule mod_tls.c>
    TLSEngine on
    TLSLog /var/log/proftpd/tls.log
    TLSProtocol TLSv1
    TLSRSACertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem
    TLSRSACertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key
    TLSVerifyClient off
    TLSOptions NoSessionReuseRequired NoCertRequest
    TLSRequired on
</IfModule>