Errors/Ruby on Rails

Common Ruby on Rails Errors

Ruby on Rails errors including ActiveRecord exceptions, routing errors, migration issues, and deployment problems.

100 errors documented with step-by-step fixes

Record not found Rails

ActiveRecord::RecordNotFound

find() couldn't locate a record with the given ID.

Record invalid Rails

ActiveRecord::RecordInvalid

A validation failed when saving.

Duplicate record Rails

ActiveRecord::RecordNotUnique

A unique constraint was violated.

Statement invalid Rails SQL

ActiveRecord::StatementInvalid

The generated SQL query is invalid.

Table does not exist Rails

PG::UndefinedTable

The database table hasn't been created.

Column does not exist Rails

PG::UndefinedColumn

A column referenced in the query doesn't exist.

Pending migrations Rails

ActiveRecord::PendingMigrationError

There are unapplied migrations.

Undefined method for nil Rails

NoMethodError: undefined method for nil:NilClass

You called a method on nil, often from a failed lookup.

Routing error Rails

ActionController::RoutingError

No route matches the request.

Parameter missing Rails

ActionController::ParameterMissing

A required strong parameter is missing.

Missing template Rails

ActionView::MissingTemplate

The view template file doesn't exist.

Double render error Rails

DoubleRenderError

The action tried to render or redirect more than once.

Invalid authenticity token Rails CSRF

ActionController::InvalidAuthenticityToken

The CSRF token is missing or invalid.

Cannot load file Rails

LoadError: cannot load file

Ruby can't find the file to require.

Wrong number of arguments Ruby Rails

ArgumentError: wrong number of arguments

A method was called with the wrong number of parameters.

Uninitialized constant Rails

NameError: uninitialized constant

Ruby can't find the class or module.

Sidekiq job retry failed Rails

Sidekiq::JobRetry::Handled

A background job exhausted all retries.

Redis connection error Rails

Redis::CannotConnectError

Can't connect to the Redis server.

N+1 query problem Rails

N+1 query Rails

Each iteration triggers a separate database query.

Connection pool timeout Rails

ActiveRecord::ConnectionTimeoutError

All database connections in the pool are in use.

ActionController::UnknownFormat in Ruby on Rails

ActionController::UnknownFormat

This Ruby on Rails error occurs when unknownformat. Check the stack trace for the exact location and fix the root cause.

ActionController::UnpermittedParameters in Ruby on Rails

ActionController::UnpermittedParameters

This Ruby on Rails error occurs when unpermittedparameters. Check the stack trace for the exact location and fix the root cause.

ActionController::BadRequest in Ruby on Rails

ActionController::BadRequest

This Ruby on Rails error occurs when badrequest. Check the stack trace for the exact location and fix the root cause.

ActionController::MethodNotAllowed in Ruby on Rails

ActionController::MethodNotAllowed

This Ruby on Rails error occurs when methodnotallowed. Check the stack trace for the exact location and fix the root cause.

ActionDispatch::Http::Parameters::ParseError in Ruby on Rails

ActionDispatch::Http::Parameters::ParseError

This Ruby on Rails error occurs when parseerror. Check the stack trace for the exact location and fix the root cause.

AbstractController::ActionNotFound in Ruby on Rails

AbstractController::ActionNotFound

This Ruby on Rails error occurs when actionnotfound. Check the stack trace for the exact location and fix the root cause.

ActionView::Template::Error in Ruby on Rails

ActionView::Template::Error

This Ruby on Rails error occurs when error. Check the stack trace for the exact location and fix the root cause.

ActionView::SyntaxErrorInTemplate in Ruby on Rails

ActionView::SyntaxErrorInTemplate

This Ruby on Rails error occurs when syntaxerrorintemplate. Check the stack trace for the exact location and fix the root cause.

ActionView::MissingExactTemplate in Ruby on Rails

ActionView::MissingExactTemplate

This Ruby on Rails error occurs when missingexacttemplate. Check the stack trace for the exact location and fix the root cause.

ActiveModel::UnknownAttributeError in Ruby on Rails

ActiveModel::UnknownAttributeError

This Ruby on Rails error occurs when unknownattributeerror. Check the stack trace for the exact location and fix the root cause.

ActiveModel::ForbiddenAttributesError in Ruby on Rails

ActiveModel::ForbiddenAttributesError

This Ruby on Rails error occurs when forbiddenattributeserror. Check the stack trace for the exact location and fix the root cause.

ActiveModel::ValidationError in Ruby on Rails

ActiveModel::ValidationError

This Ruby on Rails error occurs when validationerror. Check the stack trace for the exact location and fix the root cause.

ActiveModel::MissingAttributeError in Ruby on Rails

ActiveModel::MissingAttributeError

This Ruby on Rails error occurs when missingattributeerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::AssociationTypeMismatch in Ruby on Rails

ActiveRecord::AssociationTypeMismatch

This Ruby on Rails error occurs when associationtypemismatch. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::InverseOfAssociationNotFoundError in Ruby on Rails

ActiveRecord::InverseOfAssociationNotFoundError

This Ruby on Rails error occurs when inverseofassociationnotfounderror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::HasManyThroughAssociationNotFoundError in Ruby on Rails

ActiveRecord::HasManyThroughAssociationNotFoundError

This Ruby on Rails error occurs when hasmanythroughassociationnotfounderror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::EagerLoadPolymorphicError in Ruby on Rails

ActiveRecord::EagerLoadPolymorphicError

This Ruby on Rails error occurs when eagerloadpolymorphicerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::ReadOnlyRecord in Ruby on Rails

ActiveRecord::ReadOnlyRecord

This Ruby on Rails error occurs when readonlyrecord. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::StaleObjectError in Ruby on Rails

ActiveRecord::StaleObjectError

This Ruby on Rails error occurs when staleobjecterror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::IrreversibleMigration in Ruby on Rails

ActiveRecord::IrreversibleMigration

This Ruby on Rails error occurs when irreversiblemigration. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::DuplicateMigrationVersionError in Ruby on Rails

ActiveRecord::DuplicateMigrationVersionError

This Ruby on Rails error occurs when duplicatemigrationversionerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::DuplicateMigrationNameError in Ruby on Rails

ActiveRecord::DuplicateMigrationNameError

This Ruby on Rails error occurs when duplicatemigrationnameerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::IllegalMigrationNameError in Ruby on Rails

ActiveRecord::IllegalMigrationNameError

This Ruby on Rails error occurs when illegalmigrationnameerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::EnvironmentMismatchError in Ruby on Rails

ActiveRecord::EnvironmentMismatchError

This Ruby on Rails error occurs when environmentmismatcherror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::ProtectedEnvironmentError in Ruby on Rails

ActiveRecord::ProtectedEnvironmentError

This Ruby on Rails error occurs when protectedenvironmenterror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::NoDatabaseError in Ruby on Rails

ActiveRecord::NoDatabaseError

This Ruby on Rails error occurs when nodatabaseerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::DatabaseAlreadyExists in Ruby on Rails

ActiveRecord::DatabaseAlreadyExists

This Ruby on Rails error occurs when databasealreadyexists. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::AdapterNotFound in Ruby on Rails

ActiveRecord::AdapterNotFound

This Ruby on Rails error occurs when adapternotfound. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::ConnectionNotEstablished in Ruby on Rails

ActiveRecord::ConnectionNotEstablished

This Ruby on Rails error occurs when connectionnotestablished. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::ConnectionTimeoutError (variant) in Ruby on Rails

ActiveRecord::ConnectionTimeoutError (variant)

This Ruby on Rails error occurs when connectiontimeouterror (variant). Check the stack trace for the exact location and fix the root cause.

ActiveRecord::Deadlocked in Ruby on Rails

ActiveRecord::Deadlocked

This Ruby on Rails error occurs when deadlocked. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::LockWaitTimeout in Ruby on Rails

ActiveRecord::LockWaitTimeout

This Ruby on Rails error occurs when lockwaittimeout. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::SerializationFailure in Ruby on Rails

ActiveRecord::SerializationFailure

This Ruby on Rails error occurs when serializationfailure. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::SubclassNotFound in Ruby on Rails

ActiveRecord::SubclassNotFound

This Ruby on Rails error occurs when subclassnotfound. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::ConfigurationError in Ruby on Rails

ActiveRecord::ConfigurationError

This Ruby on Rails error occurs when configurationerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::ValueTooLong in Ruby on Rails

ActiveRecord::ValueTooLong

This Ruby on Rails error occurs when valuetoolong. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::RangeError in Ruby on Rails

ActiveRecord::RangeError

This Ruby on Rails error occurs when rangeerror. Check the stack trace for the exact location and fix the root cause.

ActiveRecord::NotNullViolation in Ruby on Rails

ActiveRecord::NotNullViolation

This Ruby on Rails error occurs when notnullviolation. Check the stack trace for the exact location and fix the root cause.

ActiveStorage::IntegrityError in Ruby on Rails

ActiveStorage::IntegrityError

This Ruby on Rails error occurs when integrityerror. Check the stack trace for the exact location and fix the root cause.

ActiveStorage::FileNotFoundError in Ruby on Rails

ActiveStorage::FileNotFoundError

This Ruby on Rails error occurs when filenotfounderror. Check the stack trace for the exact location and fix the root cause.

ActiveStorage::InvariableError in Ruby on Rails

ActiveStorage::InvariableError

This Ruby on Rails error occurs when invariableerror. Check the stack trace for the exact location and fix the root cause.

ActiveJob::DeserializationError in Ruby on Rails

ActiveJob::DeserializationError

This Ruby on Rails error occurs when deserializationerror. Check the stack trace for the exact location and fix the root cause.

ActiveJob::SerializationError in Ruby on Rails

ActiveJob::SerializationError

This Ruby on Rails error occurs when serializationerror. Check the stack trace for the exact location and fix the root cause.

Sidekiq::Shutdown in Ruby on Rails

Sidekiq::Shutdown

This Ruby on Rails error occurs when shutdown. Check the stack trace for the exact location and fix the root cause.

Rack::Timeout::RequestTimeoutException in Ruby on Rails

Rack::Timeout::RequestTimeoutException

This Ruby on Rails error occurs when requesttimeoutexception. Check the stack trace for the exact location and fix the root cause.

Rack::Utils::InvalidParameterError in Ruby on Rails

Rack::Utils::InvalidParameterError

This Ruby on Rails error occurs when invalidparametererror. Check the stack trace for the exact location and fix the root cause.

Puma::HttpParserError in Ruby on Rails

Puma::HttpParserError

This Ruby on Rails error occurs when httpparsererror. Check the stack trace for the exact location and fix the root cause.

Puma::MiniSSL::SSLError in Ruby on Rails

Puma::MiniSSL::SSLError

This Ruby on Rails error occurs when sslerror. Check the stack trace for the exact location and fix the root cause.

Sprockets::FileNotFound in Ruby on Rails

Sprockets::FileNotFound

This Ruby on Rails error occurs when filenotfound. Check the stack trace for the exact location and fix the root cause.

Sprockets::CircularDependencyError in Ruby on Rails

Sprockets::CircularDependencyError

This Ruby on Rails error occurs when circulardependencyerror. Check the stack trace for the exact location and fix the root cause.

Webpacker::Manifest::MissingEntryError in Ruby on Rails

Webpacker::Manifest::MissingEntryError

This Ruby on Rails error occurs when missingentryerror. Check the stack trace for the exact location and fix the root cause.

SassC::SyntaxError in Ruby on Rails

SassC::SyntaxError

This Ruby on Rails error occurs when syntaxerror. Check the stack trace for the exact location and fix the root cause.

Gem::LoadError in Ruby on Rails

Gem::LoadError

This Ruby on Rails error occurs when loaderror. Check the stack trace for the exact location and fix the root cause.

Bundler::GemNotFound in Ruby on Rails

Bundler::GemNotFound

This Ruby on Rails error occurs when gemnotfound. Check the stack trace for the exact location and fix the root cause.

Bundler::VersionConflict in Ruby on Rails

Bundler::VersionConflict

This Ruby on Rails error occurs when versionconflict. Check the stack trace for the exact location and fix the root cause.

Ruby: Encoding::UndefinedConversionError in Ruby on Rails

Ruby: Encoding::UndefinedConversionError

This Ruby on Rails error occurs when undefinedconversionerror. Check the stack trace for the exact location and fix the root cause.

Ruby: Encoding::InvalidByteSequenceError in Ruby on Rails

Ruby: Encoding::InvalidByteSequenceError

This Ruby on Rails error occurs when invalidbytesequenceerror. Check the stack trace for the exact location and fix the root cause.

Ruby: IOclosed stream in Ruby on Rails

Ruby: IOError: closed stream

This Ruby on Rails error occurs when closed stream. Check the stack trace for the exact location and fix the root cause.

Ruby: Errno::ECONNRESET in Ruby on Rails

Ruby: Errno::ECONNRESET

This Ruby on Rails error occurs when econnreset. Check the stack trace for the exact location and fix the root cause.

Ruby: Errno::ETIMEDOUT in Ruby on Rails

Ruby: Errno::ETIMEDOUT

This Ruby on Rails error occurs when etimedout. Check the stack trace for the exact location and fix the root cause.

Ruby: Net::OpenTimeout in Ruby on Rails

Ruby: Net::OpenTimeout

This Ruby on Rails error occurs when opentimeout. Check the stack trace for the exact location and fix the root cause.

Ruby: Net::ReadTimeout in Ruby on Rails

Ruby: Net::ReadTimeout

This Ruby on Rails error occurs when readtimeout. Check the stack trace for the exact location and fix the root cause.

Ruby: OpenSSL::SSL::SSLError in Ruby on Rails

Ruby: OpenSSL::SSL::SSLError

This Ruby on Rails error occurs when sslerror. Check the stack trace for the exact location and fix the root cause.

Ruby: JSON::ParserError in Ruby on Rails

Ruby: JSON::ParserError

This Ruby on Rails error occurs when parsererror. Check the stack trace for the exact location and fix the root cause.

Ruby: URI::InvalidURIError in Ruby on Rails

Ruby: URI::InvalidURIError

This Ruby on Rails error occurs when invalidurierror. Check the stack trace for the exact location and fix the root cause.

Ruby: RegexpError in Ruby on Rails

Ruby: RegexpError

This Ruby on Rails error occurs when regexperror. Check the stack trace for the exact location and fix the root cause.

Ruby: SystemStackError in Ruby on Rails

Ruby: SystemStackError

This Ruby on Rails error occurs when systemstackerror. Check the stack trace for the exact location and fix the root cause.

Ruby: NoMemoryError in Ruby on Rails

Ruby: NoMemoryError

This Ruby on Rails error occurs when nomemoryerror. Check the stack trace for the exact location and fix the root cause.

Ruby: ThreadError in Ruby on Rails

Ruby: ThreadError

This Ruby on Rails error occurs when threaderror. Check the stack trace for the exact location and fix the root cause.

Ruby: Frozencan't modify frozen String in Ruby on Rails

Ruby: FrozenError: can't modify frozen String

This Ruby on Rails error occurs when can't modify frozen string. Check the stack trace for the exact location and fix the root cause.

Devise::FailureApp redirect error in Ruby on Rails

Devise::FailureApp redirect error

This Ruby on Rails error occurs when failureapp redirect error. Check the stack trace for the exact location and fix the root cause.

Devise: confirmation token expired in Ruby on Rails

Devise: confirmation token expired

This Ruby on Rails error occurs when confirmation token expired. Check the stack trace for the exact location and fix the root cause.

Pundit::NotAuthorizedError in Ruby on Rails

Pundit::NotAuthorizedError

This Ruby on Rails error occurs when notauthorizederror. Check the stack trace for the exact location and fix the root cause.

CanCan::AccessDenied in Ruby on Rails

CanCan::AccessDenied

This Ruby on Rails error occurs when accessdenied. Check the stack trace for the exact location and fix the root cause.

PG::ConnectionBad in Ruby on Rails

PG::ConnectionBad

This Ruby on Rails error occurs when connectionbad. Check the stack trace for the exact location and fix the root cause.

PG::InFailedSqlTransaction in Ruby on Rails

PG::InFailedSqlTransaction

This Ruby on Rails error occurs when infailedsqltransaction. Check the stack trace for the exact location and fix the root cause.

PG::QueryCanceled: canceling statement due to timeout in Ruby on Rails

PG::QueryCanceled: canceling statement due to timeout

This Ruby on Rails error occurs when canceling statement due to timeout. Check the stack trace for the exact location and fix the root cause.

PG::TRSerializationFailure in Ruby on Rails

PG::TRSerializationFailure

This Ruby on Rails error occurs when trserializationfailure. Check the stack trace for the exact location and fix the root cause.

MySQL2::Error::ConnectionError in Ruby on Rails

MySQL2::Error::ConnectionError

This Ruby on Rails error occurs when connectionerror. Check the stack trace for the exact location and fix the root cause.

Redis::CommandError in Ruby on Rails

Redis::CommandError

This Ruby on Rails error occurs when commanderror. Check the stack trace for the exact location and fix the root cause.

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