So, I told I client I could add a shortcode handler to add youtube clips, tried it, and realised they're using sivlerstripe 2.3.2

I added the shortcode file (sapphire/master/parsers/ShortcodeParser.php) which means the page gives no errors, but it doesn't actually replace the code with the content from the handler.

Does anyone know if it's possible to get this running in 2.3.2?

I know the best option is to upgrade the site to 2.4 or even 3, but i'm only charging a few minutes work for this task...