6.40rc4 changelog:

*) conntrack - load IPv6 connection tracking independently of IPv4;
*) console - fixed "No such file or directory" warnings on upgrade reboots;
*) defconf - discard default configuration startup query with RouterOS upgrade;
*) defconf - discard default configuration startup query with configuration change from Webfig;
*) dns - made loading thousands of static entries faster;
*) fetch - fixed user and password argument parsing from URL for FTP;
*) log - work on false CPU/RAM overclocked alarms;
*) lte - added additional driver support for DWR-910;
*) smb - fixed external drive folder sharing when "/flash" folder existed;
*) smb - fixed invalid default share after reboot when "/flash" folder existed;
*) upnp - fixed firewall nat rule update when external IP address changes;

Other changes since 6.39:

*) 6to4 - fixed wrong IPv6 “link-local” address generation;
*) arp - fixed “make-static”;
*) capsman - fixed EAP identity reporting in “registration-table”;
*) dns - remove all dynamic cache RRs of same type when adding static entry;
*) ethernet - fixed forced 10Mbps full-duplex linking on 100Mbps Ethernet ports;
*) firewall - fixed “address-list” entry changing from IP to DNS and vice versa;
*) firewall - “address-list” entry “creation-time” adjusted to timezone;
*) firewall - fixed cosmetic "inactive" flag when item was disabled;
*) ike1 - fixed crash on xauth message;
*) ike1 - fixed minor memory leak on peer configuration change;
*) ipsec - enabled modp2048 DH group by default;
*) ipsec - optimized logging under IPSec topic;
*) ipv6 - fixed address becoming invalid when interface was removed from bridge/mesh;
*) pppoe - fixed warning on PPPoE server, when changing interface to non-slave interface;
*) quickset - added "Band" setting to "CPE" and "PTP CPE" modes;
*) routing - allow to disable "all" interface entry in BFD;
*) sniffer - fixed VLAN tags when sniffing all interfaces;
*) snmp - fixed limited walk;
*) switch - fixed disabling of MAC learning on CRS1xx/CRS2xx;
*) tile - fixed EoIP keepalive when tunnel is made over VLAN interface;
*) winbox - added "eap-identity" to CAPsMAN registration table;
*) winbox - added "no-dad" setting to IPv6 addresses;
*) winbox - added TR069 support;
*) winbox - do not allow to open multiple same sub-menus at the same time;
*) wireless - fixed 802.11u wireless request processing;
*) wireless - fixed EAP PEAP success processing;

Download the new 'RouterOS 6.40rc4' version here: https://www.mikrotik.com/download