Remember to make backup/export files before an upgrade and save them on another storage device;
Make sure the device will not lose power during upgrade process;
Device has enough free storage space for all RouterOS packages to be downloaded.
What's new in 7.21.1 (2026-Jan-19 17:09):
bridge - fixed dynamic switch-cpu VLAN creation (introduced in v7.21);
bridge - improved stability when using MVRP (introduced in v7.21);
certificate - fixed empty trust store handling in certain cases (introduced in v7.21);
container - changed app auto update to be off by default;
container - fixed issue where containers may not start with large mounts;
health - fixed fan and PSU state logging for MIPSBE devices;
leds - fixed power LED behavior for hAP ax S;
lte - fixed APN configuration for QMI modems in a 3G network when use-network-apn=yes is used;
switch - fixed switch type for hAP ax lite devices (introduced in v7.21);
system - fixed rare partial loss of RouterOS configuration;
To upgrade, click Check For Updates under System/Packages menu and select the stable Channel in RouterOS configuration interface, or head to our download page: http://www.mikrotik.com/download
Everything went smoothly
I encountered an issue after the update (please post about the device, configuration, and unexpected symptoms)
I encountered an issue, but solved it (please post the solution)
0voters
If you experience version related issues, then please send supout file from your router to support@mikrotik.com. The file must be generated while a router is not working as suspected or after some problem has appeared on the device
Please keep this forum topic strictly related to this particular RouterOS release.
system - fixed rare partial loss of RouterOS configuration;
Does this bug still affect v7.20.7 long-term release? If so, then surely it is advisable to switch to stable, or push a new long-term release? It may be a rare bug, but it sounds pretty critical nonetheless
7.21.1 breaks my Chateau 5G R17 ax. After installing, 5G modem always falls back to 4G and cannot connect to internet. No IP/IPv6 is acquired on lte1 interface. Downgrading back to 7.21 solves the issue. After that, 5G modem stays at 5G NSA an I am getting an IP/IPv6 on lte1 interface.
I can reproduce that by upgrading again to 7.21.1. Created ticket: SUP-209010
[EDIT]
Fixed by provided testbuild from MikroTik support. According to MikroTIk, fix will be in next stable release.
Just upgraded my Chateau R17 to RouterOS 7.21.1 and immediately lost LTE connectivity. The router physically connects to the cellular network but seems to be unable to get an IP address for its LTE interface. Downgrading back to 7.21 fixes the problem.
Hope this issue will be fixed in next versions of the system.
I see no changes to wifi/wifi-qcom-ac in the changelog, but one of my wireless clients (Intel AX200) went completely nuts after upgrade to 7.21.1. It was disconnecting about every 30 seconds. It was unusable. It went for a few hours this way. I tried rebooting, checked frequencies, nothing helped. After downgrade to 7.21 this client's connection is rock solid again. Don't know what caused this.
RB5009, using VLAN filtering with l2hw, intra vlan IP routing and NAT towards ISP, the usual firewall rules and wireguard: Updated from 7.21.0 to 7.21.1 without issues so far.
Chateau R17: Same issue as reported by others: lte is reported as connected, but does not move any data and hence fails to even get an IP. lte works again after reverting to 7.21.0
