Thing example error?

I have looked at the example in
Thing exec:command:myscript [command=“php ./configurations/scripts/script.php %2$s”, transform=“REGEX((.*?))”]

I have in my default.things

Thing exec:command:elkedel_voltage [command="/usr/local/bin/ -t -j '{\"emeter\":{\"get_realtime\":{}}}'", interval=15,timeout=4,transform="REGEX(\"voltage\":(\\d*?))"]
Thing exec:command:elkedel_power [command="/usr/local/bin/ -t -j '{\"emeter\":{\"get_realtime\":{}}}'", interval=15,timeout=4,transform="REGEX(\"power\":(\\d*?))"]
Thing exec:command:elkedel_command [command="/usr/local/bin/ -t -c %2$s", interval=15,timeout=4"]

But I get the error in the log:
2017-03-16 00:06:16.083 [ERROR] [hab.binding.exec.handler.ExecHandler] - An exception occurred while formatting the command line with the current time and input values : 'Format specifier '%2$s''

If I change the format to \%2$S it works.