'The parameter' debug.error_handler.throw_at 'must be defined' error after upgrading to Symfony 2.6

Question

After upgrading Symfony from Composer to version 2.6, it gives the following error:

[Symfony \ Component \ DependencyInjection \ Exception \ InvalidArgumentException] The debug.error_handler.throw_at parameter must be defined.

Answer 1

manual clear application cache - delete all files in / app / cache: rm -r app/cache/*

and then clear the cache for the necessary environment:

app/console cache:warmup --env=prod