Help with hmt

[jub]

When I try Extract BSP/Model Selections on Halo Map Tools v3.5 I chose the file to extract to and then an error comes up saying
"An unhandled exception has occured in a componentin your
application. Click Continue and application will ignore this error and
attempt to continue.

Illegal characters in path."

I don't know how to fix this so plz post if you know how.