CONFIGURATION_ERROR Remove and recreate channel

setting an mqtt channel by code i made a mistake and now thing is offline with the message

Remove and recreate: mqtt:topic:b94727f5:nspanel:ns_thermostat_switch

but the channel is gone from code and from channels list.
How can i edit it or remove it and recreate?

Are you using xxx.things files or GUI?

just GUI ,latest stable openhab3.2

used gui code section to edit it and i did a typo …so next thing the channel disappeared from code and from channels list
i can find the item linked to the faulty channel but i cant edit it there…

Restore a backup of the things JSONDB. A few backups are kept around in $OH_USERDATA/jsondb/backup. Restore the one without the typo.

thnx i have solved it.I did not know about backups so ,i stoped openhab,found the typo in things JSONDB and fixed it.Then started openhab …it seems working fine.