R markdown beamer presentation returning undefined control sequence-CodePudding

Whenever I tried to knit R markdown in beamer presentation format, it keeps on giving me undefined control sequence.

It is fraustrating because it worked fine until yesterday and I have no idea what I changed that causes this error. To show that my code is not the source of the problem, I simply tried to knit an empty page.

code:

---
title: "untitled"
output: beamer_presentation
---

Output:

output file: a.knit.md

! Undefined control sequence.
<argument> ...{subsubsection}\addtobeamertemplate 
                                                  {theorem begin}{\expandaft...
l.322 }{}

My original file returns the exaclty same error message.

I tried:

reinstall LaTeX
reinstall RStudio
upgrade all packages in R

Any idea how to fix this?

CodePudding user response：

This was just fixed by @UlrikeFischer. @JosephWright is preparing a new beamer release as we speak, it should be available as beamer v3.67 on ctan tomorrow.

As a temporary workaround, place these two files in the folder of your .rmd file:

(don't forget to delete these files again once you have the new beamer version, otherwise they might interfere with future updates)