The language that is used for the description of the default resource pack doesn't match up with the English language like the other built-in packs do when the language is set to Pirate Speak,
MC-264403
Pirate Speak description of default resource pack is mismatched
Resolved
Invalid
0
Issues with languages other than English (US) are not accepted here as they are community made. You can correct this on crowdin yourself, but this case was a deliberate choice by the translators, and your suggested version of the string will probably not be accepted.