The simplest way to reproduce:

1. Create a "Blog" [blog] content type with "Title" [title] text line field.
2. Save the "Blog" content type.
3. Add "Related posts" [related_posts] content relations field. And choose "Blog" in the "Allowed Content Types" configuration. Save the "Blog" content type.
4. Run "php bin/console ezplatform:graphql:generate-schema" to update the schema.
5. Rename "Blog" content type: change it's identifier from "blog" to "blog_post".
6. Run "php bin/console ezplatform:graphql:generate-schema" to update the schema.

Expected result

The schema is updated

Actual result

Following error message is shown:

In Handler.php line 266:                                                                                               
  Could not find 'eZ\Publish\SPI\Persistence\Content\Type' with identifier 'ID: blog, Status: 0'