Keep a copy on a USB stick. You never know when you’ll encounter an old RB750 that refuses to talk to anything else.
Ensure your RouterOS is configured to require modern encryption standards that Winbox 3.28 supports. winbox 3.28
Winbox serves as the primary graphical user interface (GUI) for MikroTik’s RouterOS Keep a copy on a USB stick
WinBox - RouterOS - MikroTik Documentation - Support Service winbox 3.28