read_lines() warning message and the problems() function

[mrhumanzee]

I'm working with the binary object casetable_bin. When I tried to parse this object into a string vector using the command casetable_lines <- read_lines(casetable_bin), I received the following warning message:

One or more parsing issues, call problems() on your data frame for details, e.g.: dat <- vroom(...) problems(dat)

However, running the command readr::problems(casetable_lines) returns nothing. Furthermore, running the command attributes(casetable_lines) returns only the NULL value. Where does readr store the problems it detects in objects?