ParseException: The YAML value does not appear to be valid UTF-8

Sometimes Symfony throws up the most peculiar of error messages.

I had a situation where I had two config (.yml) files, one environment overriding the other.

Now, what was particularly confusing about this situation was that I had copied and pasted the config (not very DRY) from the first file to the second.

This wasn’t a new project – both files had been around for a long time, but it was the first time I was using the second file properly.

The idea in this instance was the second config file would inherit all the first config files settings, but over rule the ones I had changed.

As soon as I did this, however, I got the following:

code error text for Google’s benefit:

Whoops, looks like something went wrong.

1/1ContextErrorException: Warning: htmlspecialchars(): Invalid multibyte sequence in argument in /mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Debug/ExceptionHandler.php line 302
in /mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Debug/ExceptionHandler.php line 302
at ErrorHandler->handle('2', 'htmlspecialchars(): Invalid multibyte sequence in argument', '/mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Debug/ExceptionHandler.php', '302', array('args' => array(array('string', '')), 'result' => array(), 'key' => '0', 'item' => array('string', '')))
at htmlspecialchars('', '11', 'UTF-8') in /mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Debug/ExceptionHandler.php line 302
at ExceptionHandler->formatArgs(array(array('string', ''))) in /mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Debug/ExceptionHandler.php line 158
at ExceptionHandler->getContent(object(FlattenException)) in /mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Debug/ExceptionHandler.php line 117
at ExceptionHandler->createResponse(object(ParseException)) in /mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Debug/ExceptionHandler.php line 74
at ExceptionHandler->handle(object(ParseException))
Exception thrown when handling an exception (Symfony\Component\Debug\Exception\FlattenException: The YAML value does not appear to be valid UTF-8.)

1/1ParseException: The YAML value does not appear to be valid UTF-8.
in /mnt/project/my-project/vendor/symfony/symfony/src/Symfony/Component/Yaml/Parser.php line 59

A classic Symfony blow up.

Now, whilst this may be a Symfony project, it is not a Symfony problem!

The problem is the encoding of the file itself. This sounds like it might be a total pain to fix, but if you are using PHPStorm it’s actually very, very easy.

How to Fix ParseException: The YAML value does not appear to be valid UTF-8

Open the file in PHPStorm.

Take a look in the bottom right corner:

Notice – I am using Windows here, so the default file encoding type is what caught me out.

Click the text ‘windows-1252’ or whatever you have here that is not UTF-8.

Select UTF-8.

You may get a little pop up warning you that your file will be converted to UTF-8.

Take a back up if you aren’t sure, but otherwise, convert it.

Upload the file (or do nothing if using shared mounts in Vagrant), and success, we have captured the enemies intelligence.