A firewall rule on your PC or intermediate network is dropping TCP port 8291 (the default Winbox port), or your PC is on a different subnet.
192.168.88.1:9999
Comprehensive Guide to Winbox Loader v2.218: Features and Safe Download Practices winbox loader v2 218 download link
Using an outdated version of management software introduces severe vulnerabilities into your infrastructure: A firewall rule on your PC or intermediate