Doctrine\Common\Util\Inflector has been depreciated in favour of using Doctrine\Inflector\Inflector in newer versions of Doctrine2 used in the file library/OSS/Form/Trait/Doctrine2.php.

I came across this problem after a Gentoo system update, but I'm not sure what triggered the issue, it could have been caused by 'compositor upgrade'.

I have created a patch that fixes the issue