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

Question

After updating Symfony with Composer to version 2.6 it gives this error:

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

Answer 1

manualy clear application cache - remove all files in /app/cache: rm -r app/cache/*

and then warmup cache for needed environment like that:

app/console cache:warmup --env=prod