Is there any way to convert SAS V8 or V9 transport files (.xpt)to CSV?

library(haven)
cprot_file <- "ds.xpt"
csv_file <- "ds.csv"
cprot_data <- read_xpt(cprot_file)
write.csv(cprot_data, file = csv_file, row.names = FALSE)

It looks, from the Error message, that you may have a typo somewhere: the file name there seems to be ds.xpt not dps.xpt.

my bad i type the wrong file name while posting here.

Are you still having the problem?

yes
i have been searching but couldn't find a solution