mongodb/mongoid · error · Mongoid::Errors::UnrecognizedResolver

The model resolver %{resolver} was referenced, but never reg

Error message

The model resolver %{resolver} was referenced, but never registered.

What it means

Error "The model resolver %{resolver} was referenced, but never registered." thrown in mongodb/mongoid.

Source

Thrown at lib/mongoid/model_resolver.rb:59

      # Returns the resolver instance that corresponds to the argument.
      #
      # @param [ nil | true | false Symbol | String | Mongoid::ModelResolver::Interface ] identifier_or_object
      #   When nil or false, returns nil. When true or :default, corresponds to the default resolver.
      #   When any other symbol or string, corresponds to the registered resolver with that identifier.
      #   Otherwise, it must be a resolver instance itself.
      #
      # @raise Mongoid::Errors::UnrecognizedResolver if the given identifier is a
      #   symbol or string and it does not match any registered resolver.
      #
      # @return [ Mongoid::ModelResolver::Interface ] the resolver instance corresponding to the
      #   given argument.
      def resolver(identifier_or_object = :default)
        case identifier_or_object
        when nil, false then nil
        when true, :default then instance
        when String, Symbol
          resolvers.fetch(identifier_or_object.to_sym) do |key|
            raise Mongoid::Errors::UnrecognizedResolver, key
          end
        else identifier_or_object
        end
      end

      # Register the given resolver under the given name.
      #
      # @param [ Mongoid::ModelResolver::Interface ] resolver the resolver to register.
      # @param [ String | Symbol ] name the identifier to use to register the resolver.
      def register_resolver(resolver, name)
        resolvers[name.to_sym] = resolver
        self
      end
    end

    # Instantiates a new ModelResolver instance.
    def initialize
      @key_to_model = {}

View on GitHub (pinned to 0da0e23d71)

When it happens

Trigger: Thrown at lib/mongoid/model_resolver.rb:59 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of mongodb/mongoid@0da0e23d71 (2026-08-23). Data as JSON: /api/errors/4743931d066818f0. Report an issue: GitHub.