The Behavior tab has a checkbox dedicated to the following settings:
- Reporting back to the clients errors that occur when changing some permissions;
- Allow client identification string not terminated by CRLF.
The first option allows administrators to re-enable error messages generated by unsuccessful attempts to set file permissions. When enabled, these messages are sent to the client, providing more detailed feedback on why the operation failed.
The second option relaxes protocol compliance for legacy or non-compliant clients, allowing identification strings not terminated with CRLF. This became relevant starting with version 1.12.0, when SFTP support moved to a stricter SSH library that enforces the requirement by default — if a client that used to connect fine suddenly can’t after updating, this is usually why. Use with caution, monitor logs and encourage users to update to fully compliant clients.
Note: Prior to release 1.10.0, the Behavior tab in FileZilla Pro Enterprise Server allowed enabling or disabling the insecure ssh-rsa key exchange algorithm during key exchange. Starting with version 1.10.0, more granular configuration options have been introduced in a dedicated Cryptographic algorithms tab, providing administrators with enhanced control over encryption settings.
Related Topic: