Invalid marker content in userpoints.module

I got this error while using extractor.php file to get *.pot file from userpoints.module, anybody knows how to fix it?

Starting.

Processing userpoints.module...
Invalid marker content in userpoints.module:296
* format_plural($points,$singular,$plural)

Processing userpoints.install...
Processing contrib/userpoints_reset.module...
Processing contrib/userpoints_retroactive.module...

Done.