Upgrading Symfony 2.2 to 2.3 causes silent 500 errors

Question

I just upgraded my Symfony 2.2 installation to Symfony 2.3. I was abe to get "composer update" to run with no errors, but this has caused every route in my application to return a blank page. If I check the network tab on my JavaScript console, I see that a 500 Internal Server Error is being thrown, but have no insight as to what might be causing it. Any ideas? Here's my composer.json file:

{
"name": "symfony/framework-standard-edition",
"license": "MIT",
"type": "project",
"description": "The \"Symfony Standard Edition\" distribution",
"autoload": {
    "psr-0": { "": "src/" }
},
"require": {
    "php": ">=5.3.3",
    "symfony/symfony": "2.3.*",
    "doctrine/orm": ">=2.2.3,<2.4-dev",
    "doctrine/doctrine-bundle": "1.2.*",
    "twig/extensions": "1.0.*",
    "symfony/assetic-bundle": "2.3.*",
    "symfony/swiftmailer-bundle": "2.3.*",
    "symfony/monolog-bundle": "2.3.*",
    "sensio/distribution-bundle": "2.3.*",
    "sensio/framework-extra-bundle": "2.3.*",
    "sensio/generator-bundle": "2.3.*",
    "jms/security-extra-bundle": "1.5.*",
    "jms/di-extra-bundle": "1.4.*",
    "incenteev/composer-parameter-handler": "~2.0",
    "friendsofsymfony/jsrouting-bundle": "*",
    "sandeepshetty/shopify_api": "dev-master@dev"
},
"scripts": {
    "post-install-cmd": [
        "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile"
    ],
    "post-update-cmd": [
        "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile"
    ]
},
"config": {
    "bin-dir": "bin"
},
"minimum-stability": "dev",
"prefer-stable": true,
"extra": {
    "symfony-app-dir": "app",
    "symfony-web-dir": "web",
    "incenteev-parameters": {
        "file": "app/config/parameters.yml"
    },
    "branch-alias": {
        "dev-master": "2.3-dev"
    }
}
}

Answer 1

Inspect your logifles in order to find the exception... app/logs/dev.log or app/logs/prod.log depending on which environment you are trying to access.

And clear your cache :-)

app/console cache:clear

Answer 2

You need to enable it manually in 2.3.

Debug::enable();

See: https://github.com/symfony/symfony-standard/blob/2.3/UPGRADE-2.3.md

Answer 3

Update those lines from your composer.json thouse versions are not supported by symfony >= 2.3

Before

"jms/security-extra-bundle": "1.5.*",
"jms/di-extra-bundle": "1.4.*",

After

"jms/di-extra-bundle": "dev-master",
"jms/security-extra-bundle": "dev-master",

Regards.