Symfony2 Web Debug Toolbar 500 Internal Server Error based on getTemplateClass

I came across a strange issue today whilst developing on symfony2. On a very bare installation of symfony, every time I refreshed the page, I came across the following error:

An error occurred while loading the web debug toolbar (500 internal server error)
I'd then have the option to view the profiler or cancel.
On viewing the profiler, I saw the following:

Error: Maximum function nesting level of '100' reached, aborting!
500 Internal Server Error - FatalErrorException
and the initial stack trace started as:

$class = substr($this->getTemplateClass($name), strlen($this->templateClassPrefix));
    return $this->getCache() . '/' . $class[0] . '/' . $class[1] . '/' . $class . '.php';
public function getTemplateClass($name, $index = null)
    return $this->templateClassPrefix.hash('sha256', $this->getLoader()->getCacheKey($name)) . (null === $index ? '' : '_' . $index);
After that, the same few lines were repeated over and over, until the maximum nesting level was hit:

at Twig_Environment->loadTemplate ()
in app/cache/dev/classes.php at line 4754

at Twig_Template->loadTemplate ()
in app/cache/dev/twig/9/1/91a16e803287d3661e6e45ff141c7445cf0fd1e6c0ab8ff1494ef7ebe3c9a481.php at line 11

at __TwigTemplate_91a16e803287d3661e6e45ff141c7445cf0fd1e6c0ab8ff1494ef7ebe3c9a481 ->__construct () 
in app/cache/dev/classes.php at line 3181

The problem

Loading up the cached Twig Template showed me that it seemed to be including itself at the top of the file, causing the infinite recursion!

The solution

Force composer to use a stable version of twig by adding the following to require section of composer.json:
"twig/twig": "@stable"
Update your composer dependencies, and the error should disappear!


Valdese commented on

Hey @Nair thanks for your solution
But it not work for me.

Anuj Nair commented on

Hi Valdese,
Do you have any more details on the issue you're seeing?
Have you tried increasing your PHP max nesting level?

Prakash commented on

worked on Symfony 3.0 also
Just installed the composer and appended the line as suggested above by Anuj
Run composer update within your project directory
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