Problem: You encounter an error reading NameError: uninitialized constant Something or NameError: uninitialized constant Object::Something (with various class names in place of Something).
Solution: You've most likely referred to a class or module that doesn't exist. Most likely, you've forgotten to require a gem or library needed for the code to work, or you've made a typo. Another possibility is that the class you'd like to refer to is in another module. If that's the case, you'll have to refer to it with its full name as in the following code.
#!/usr/bin/env ruby module MyModule class MyClass; end end c = MyModule::MyClass.new