It may be an escaping issue. Try running the original command (without the ui escapes) from the shell.
Also, try running it from the shell with the escapes:
Former Nagios employee
"It is turtles. All. The. Way. Down. . . .and maybe an elephant or two."
VI VI VI - The editor of the Beast!
Come to the Dark Side.
Alright. Looks like the escapes are most likely necessary. Change your command to include the escapes. Once you do so, the "test command" option will no longer work as it will double escape, but the check itself should start working.
Former Nagios employee
"It is turtles. All. The. Way. Down. . . .and maybe an elephant or two."
VI VI VI - The editor of the Beast!
Come to the Dark Side.