Warning message: Status 127


I am super new to R/Rstudio and Coding so this may be super basic, but…

A code was written for me, it has run perfectly fine before, but this time i’ve gone to run it (don’t think anything has changed) and I keep getting an error when trying to create the file directory (see below).

Firstly, what does status 127 actually mean (i can’t find this anywhere, other than people asking what to do when they get this status… and it seems to be very case specific)?
Secondly, can anyone help with how to rectify this? (and why it may have happened in the first place when the code has run smoothly before?)

# mass spec negative dataset
if (1) {
  group_col <- "Group"
  id_col    <- "CowID"
  time_col  <- "Day"
  out_dir   <- "MASS_SPEC_C18neg_ALL"

  # read in our data
  dat <- read.csv("C18neg_serum_MINGSHUfilter_20cows.csv")

  data_col <- 19:ncol(dat)
#> # create output folder
#> system(paste("mkdir", out_dir))
#**Warning message:**
#**running command 'mkdir MASS_SPEC_C18neg_ALL' had status 127**