[Debug] Fixed `ClassNotFoundFatalErrorHandler`

After running the test suite, this produced a Fatal Error. Having continue in a child method is not allowed.

| Q             | A
| ------------- | ---
| Bug fix?      | [yes]
| New feature?  | [no]
| BC breaks?    | [no]
| Deprecations? | [no]
| Tests pass?   | [yes]
| Fixed tickets | None
| License       | MIT
| Doc PR        | None