Ошибка вида:
An exception has been thrown during the rendering of a template [Semantical Error] The annotation ... in class ... was never imported. Did you maybe forget to add a use statement for this annotation? in .... (which is being imported from .../config/routes/annotations.yaml). Make sure annotations are installed and enabled)
Решение
В качестве решения можно использовать в любом стартовом файле проекта ( в symfony 4 можно использовать config/bootstrap.php) код, вида:
