From plugin page /nomini -- Despawn your minicopter - not working.

/nomini- you get message in chat saying "you are trying to spawn minicopter to far away.", I thought /nomini should kill your mini, anyway at the moment this command does nothing. In previos versions it was respawning  mini instead of killing it

A semi-recent update added the MaxNoMiniDistance option which affects how far away from the mini you can do /nomini. You can increase it to allow using /nomini from farther away.

The "you are trying to spawn minicopter to far away" string means your localization file is out of date. If you haven't made any customizations to it, you can delete the oxide/lang/en/SpawnMini.json file and reload the plugin to regenerate it with the new strings.

In previos versions it was respawning  mini instead of killing it

That was probably a bug. The current behavior of it just despawning it seems to be the desirable behavior.

So nomini works, the issue is with plugin not overwriting config so need to remove old config before updating plugins and then all work as should.