Discord error 40061: Tag names must be unique

You tried to create or modify a forum or media channel whose available_tags array contains two tags with the same name. Discord requires tag names within one channel to be unique, case-sensitively distinct as far as the API is concerned. The error comes from Create Guild Channel or Modify Channel when the tag list is included.

Bots that manage forum channels (support portals, suggestion boards, auto-tagging bots) run into this when they rebuild the tag list from an external source and the source has duplicates, or when they append a new tag without checking that a tag with that name already exists. Because Modify Channel replaces the whole available_tags array, any duplicate anywhere in the list fails the entire update.

{
  "message": "Tag names must be unique",
  "code": 40061
}

Treat tag name as a unique key in whatever store backs your bot's forum configuration, and always reconcile against the live channel before writing. Add a validation step in your config loader that rejects duplicate tag names up front.

Forum tag management is a full-array replace, which makes it a natural place for a reconciliation function: fetch, merge by name, dedupe, write. The 20-tag budget and tag name length are on the Discord limits page; structural tag errors beyond duplication (too many, too long) come back as 50035 with the field named.