A number of possible problems. Take a look at Print Issues on
my site.
When you have worked through the relevant ones, if you are
still stuck then post back with a bit more information.
This topic belongs in Printed Documentation, not webhelp
assuming your webhelp is generating OK.
Help others by clicking Correct Answer if the question is answered. Found the answer elsewhere? Share it here. "Upvote" is for useful posts.