License allows
From MikroTik Wiki
Your software can be upgraded only up to a certain version of RouterOS, for example in the following router, license upgrades will be possible only until up to the last version of RouterOs v3:
[normis@Demo_v2.9] > system license print
software-id: "LF15-2JT"
upgradable-to: v3.x
nlevel: 5
features: extra-channels
[normis@Demo_v2.9] >
If you are trying to upgrade this router to RouterOS v4, then it will not allow you to do this. You will have to purchase a license for v4 and apply it. Then the `upgradable-to` value will change.
Older Routers
If you do not see the `upgradable-to` value in this menu, you probably have RouterOS older than 2.9.27, in this case - it depends on what date it shows in this menu.
- if the date is in future, upgrade is possible via all known upgrade methods, including FTP
- if the date is in the past, upgrade is still possible, but only via Netinstall
