dear sir any one help me i have basebox 5 which firmware corrupt than i install firmware 5.26 via netinstall than install success device is on properly than logging in device show in front you have no license please insert licence other device is working stop in 24h .
so dear sir what will be do to recover licence
please help me
Don’t write in user forum, write to support. We can’t help you, they can.
Worry not, just upgrade to the last version of RouterOS it was working with. I’ve did this to myself a few times already. Usually when RB SXT SA5 have factory firmvare 6.39.2 and you try
to downgrade to older version this will happen. So just upgrade your RouterOS back to original RouterOS version. 6.39.2 or higher should do the trick. Good luck!
Basebox AC has been released with 6.x version of RouterOS, you can downgrade it to 5.x, just use netinstall again and install 6.x version on it and license will be restored.
You are right and it’s nice and dandy but maybe he doesn’t have easy access to his basebox to netinstall it. It might be 50m-60m high on chimney. 
That’s why it’s better to just upgrade back to original RouterOS where his license worked just fine. When something like this happens you need a quick solution. Climbing on chimney within a few hours isn’t alway ideal solution. I think that’s why he really needed our help othervise he could just save configuration and change basebox.