Rmarkdown Cannot Run Chunk but Can Run in Console

[cderv]

For reference, this is a duplicate of an issue posted in Github already:

Rmarkdown Cannot Run Chunk but Can Run in Console R Markdown rstudio

@chenyinggao for next time please reference when you cross post:

FAQ: Is it OK if I cross-post?

Posting the same question both here and on other sites Posting the same question to multiple forums at the same time is often considered impolite. We don't completely ban such cross-posting, but we ask you to think hard before you do it and to follow some rules. Cross-post sparingly Rather than post the same thing here and elsewhere from the get-go, post in one place at a time. Let enough time go by (think days, not hours) before you take your question somewhere else. Sometimes people at another site may suggest you post here if your question doesn't fit within the scope of the other site. Always link to your other posts, and update everywhere with any solution…