While installing a new crontab from a file, an error occured.

Error in cron: bad minute
errors in crontab file, can't install

Since the file was previously edited on Windows, line breaks consisted of a CRLF, which breaks the crontab impoort. To convert thes to LF, I used a command taken from here.

cat input.file | sed 's/\r$//' > output.file