R markdown错误：无法生成HTML文件

Question

I can't produce an HTML document from any .Rmd file by pressing the Knit HTML button in R Studio, including the sample document that summarizes and plots the cars dataset. Here's the error message that I get:

Error: unrecognized fields specified in html_dependency: attachment
Execution halted

However, I can produce the HTML document by running the command knit2html("file.Rmd") . The Knit PDF button also functions properly. Does anyone have an idea about how to fix this error?

Here's the sample .Rmd file that I have:

title: "Untitled"
author: "blakeoft"
date: "Friday, September 12, 2014"
output: html_document
---

A summary:

```{r}
summary(cars)
```

Answer 1

升级到RStudio版本0.98.1056（2014年9月9日发布）后，我遇到了同样的问题。

Answer 2

As I've answered on another thread , updating RStudio didn't work for me. So I tried updating all R packages ( Tools > Check for Package Updates... ) and then it worked.