Question: This sounds very simple, but I am frustrated for the past few hours to get this done.
I am not able to see "Macros" sub menu under "Tools" menu in Visual Studio 2008. 

I go to Tools->Customize->Commands. 
Select Tools under Categories and click Rearrange Commands. Instead of showing me the Tools Menu it shows me Files. 

Am I doing something wrong? Or is it a bug in VS 2008?

Answer: 
It's possible to get the given error if your class names don't match inflections (like acronyms) from `config/initializers/inflections.rb`.

For example, if your inflections include:

```
ActiveSupport::Inflector.inflections(:en) do |inflect|
  inflect.acronym 'DOG'
end

```

then you might need to make sure the class in your migration is:

`class CreateDOGHouses < ActiveRecord::Migration[5.0]`

rather than:

`class CreateDogHouses < ActiveRecord::Migration[5.0]`

Not super common, but if you generate a migration or a model or something, and then add part of it to inflections afterwards it may happen. (The example here will cause `NameError: uninitialized constant CreateDOGHouses` if your class name is `CreateDogHouses`, at least with Rails 5.)
The top answer solved for me. Just leaving this here in case it helps.

### Example

If your migration file is called

```
20210213040840_add_first_initial_only_to_users.rb

```

then the class name in your migration file should be

```
AddFirstInitialOnlyToUsers

```

Note: if the class name doesn't match, it will error even if the difference is just a lower case `t` instead of an upper case 'T' in 'To' - so be careful of that!