In referencing your top post, I think you may need to wrap the last part of your service command in quotes. You have:
Trycheck_command check_nt!USEDDISKSPACE!-l c -w 80 -c 90
If you have something that has spaces in it like: -l c -w 80 -c 90 being sent as a single $ARGx$, then usually you need to wrap it in quotes.check_command check_nt!USEDDISKSPACE!'-l c -w 80 -c 90 '