Kixstrip has a lot of possibilities.

Simple calling: kixstrip
returns date and time information.

Calling: kixstrip ?
returns help information.

Calling: kixstrip input.kix output.kix /block_check
will verify your kixtart code.

Calling: kixstrip input.kix output.kix /debug
will insert additional debugging code to your script which will show
- which lines were executed.
- what was the time of execution.
- what was the error status of previous line.

Calling: kixstrip input.kix output.kix /performance
shows which part of your script consumes most of your time.

For additional information see our site:
symbol on our homepage has been linked to related http://kixtart.org topic.

greetings.

btw: the message "script error: in expression!" has nothing to do with your call.
you will not get an error even when specified script doesn't exist.
also the message should be something like "script error: unknown command.".

btw: a way to find your problem during execution is using our kixstrip
tool with the option /DEBUG. during execution it will show you exactly what
the last line of execution was.

btw: can you put your code on the board or send us a copy of it.