LoadError

LoadError is raised when Ruby cannot load a file via require or load. This usually means the file doesn't exist, the gem isn't installed, or the load path is incorrect.

Common causes

• Required gem is not installed
• Typo in require statement
• File not in load path ($LOAD_PATH)
• Missing Bundler.require in Rails
• Circular require dependencies

How to fix it

• Install missing gem: gem install gem_name
• Add gem to Gemfile and run bundle install
• Check for typos in require path
• Use require_relative for local files
• Verify file exists at expected path

Example

# Error example
require 'nonexistent_gem'  # => LoadError: cannot load such file -- nonexistent_gem

# Fix by installing the gem
# $ gem install the_gem
require 'the_gem'

# For local files, use require_relative
require_relative './lib/my_class'

# Or add to load path
$LOAD_PATH.unshift('./lib')
require 'my_class'

Related errors