Error when rendering rmarkdown pdf with table of contents

Question

The following YAML

---
title: 'Hello'
author: "Me"
output: 
  pdf_document   
    
---

works fine to render a pdf document. However, adding a table of contents argument to the YAML

---
title: 'Hello'
author: "Me"
output: 
  pdf_document:
    toc: yes
       
---

gives the following error:

! Undefined control sequence.
l.1 \babel@toc
               {spanish}{} 

I read that reinstalling the package babel was working for someone, but not for me, so any help is appreciated. Thanks!