csv - R code suddenly stopped working in tidy text -

i trying word analysis on data in r. imported 1 column of data text responses survey r using read.csv. named 1 of columns "text" . code working fine few days ago , giving me error. code entering:

library(dplyr)  library(tidytext)  a1<-read.csv("/users/laura/documents/a1.csv")  colnames(a1)= c("text")  a1<-a1%>%unnest_tokens(word, text) 

the error getting says this:

error in check_input(x) : input must character vector of length or list of character vectors, each of has length of 1.

my data didn't change, code i'm using didn't change. :( don't understand why happening , new r... there package need load maybe had loaded before , didn't realize it?

here link data: https://www.dropbox.com/s/amg12jp9qx98slz/a1.csv?dl=0

thanks help

i used data provided on dropbox , following code seems running me no problems. maybe try reading in not csv?

library(dplyr) library(tidytext) library(readr)  a1 <- data_frame(text = read_lines("~/downloads/a1.csv")) %>%     mutate(line = row_number())  tidya1 <- a1 %>%     unnest_tokens(word, text)  tidya1 #> # tibble: 332 × 2 #>     line  word #>    <int> <chr> #> 1      1 empty #> 2      1  #> 3      1   cup #> 4      1  step #> 5      1    on #> 6      1   #> 7      1  line #> 8      2  safe #> 9      2 space #> 10     3 empty #> # ... 322 more rows