Did you try KG's other suggestion?:
/!load -rs script.mrcMake sure you put that ! there.
Something, probably a script, is making you send the command /-rs, however, using /! ignores any aliases you may have set and uses the mIRC command. If you use /!load -rs it should work.
If not, try downloading a separate mIRC (only from
here) and installing it in a different directory, then trying to use that command with the clean and fresh mIRC.
G'luck!
Regards