when I start Desktop Rstudio every time, I get an

问题:

after I login the Desktop Rstudio, the following message will appear:

Error in yaml.load(readLines(con), error.label = error.label, ...) : 
  object 'C_unserialize_from_yaml' not found
Error in yaml.load(readLines(con), error.label = error.label, ...) : 
  object 'C_unserialize_from_yaml' not found
Error in yaml.load(readLines(con), error.label = error.label, ...) : 
  object 'C_unserialize_from_yaml' not found
Error in yaml.load(readLines(con), error.label = error.label, ...) : 
  object 'C_unserialize_from_yaml' not found
Error in yaml.load(readLines(con), error.label = error.label, ...) : 
  object 'C_unserialize_from_yaml' not found
and I try to reinstall R and Rstudio with the newest program,it still appear error again.
when I start R program ,it can work with no error. Only Rstudio, and I try to rename the directory"C:\Users\Administrator\AppData\Local\RStudio-Desktop" in another name, Let it create when Rstudio launch,the error message again. 
And I can't knit some Rmd file working normal, it will appear following error:
Error in yaml::yaml.load(string, ...) : 
  找不到对象'C_unserialize_from_yaml'
Calls: <Anonymous> ... parse_yaml_front_matter -> yaml_load_utf8 -> <Anonymous>
停止执行

Who can help me to slove the problem.Thanks very much.

回答1:

I reverted to yaml R package version 2.1.14 and it fixed it for me. https://cran.r-project.org/src/contrib/Archive/yaml/

Use this R command to install the package from source (provided the working directory is set to where the R package is): install.packages("yaml_2.1.14.tar.gz", repos = NULL)

回答2:

You can do it by

require(devtools)
install_version("yaml", version = "2.1.14", repos = "http://cran.us.r-project.org")

It resolved my issue