crontool
Paste a schedule, read it in English, see the next runs.

Fix "errors in crontab file, can't install"

This error means crontab rejected your file during save. Almost always it's a malformed schedule line, a missing final newline, or a comment/variable written incorrectly.

What the error means

When you save from crontab -e, crontab validates the file. If any line is malformed it prints errors in crontab file, can't install and keeps the old crontab.

Common causes

  • Wrong number of fields — a schedule needs exactly 5 time fields then the command. A missing field or an extra space in the wrong place breaks it.
  • Bad value — e.g. minute 60 or month 13. Ranges are minute 0-59, hour 0-23, day 1-31, month 1-12, weekday 0-7.
  • No trailing newline — the last line must end with a newline. Add a blank line at the end.
  • Unescaped percent — a literal % in the command must be written as \%.

How to find it

Crontab reports the line number. Re-run crontab -e, go to that line, and fix the field count or value. When it saves cleanly the error is gone.

FAQ

What causes 'errors in crontab file, can't install'?

A malformed line: wrong number of fields, an out-of-range value like minute 60, a missing final newline, or an unescaped % in the command.

How do I find which line is wrong?

Crontab prints the offending line number. Open crontab -e, jump to that line, and correct the field count or value; it installs once every line is valid.

Does the crontab file need a trailing newline?

Yes. The last line must end with a newline. Add a blank line at the end if saving fails.