Cannot view topics in generated HTML help

I am using RoboHelp HTML Version 11 with Windows 7 Enterprise/Service Pack 1. My problem is with generating HTML help files. It appears to generate and I get the message that it ran successfully. It even generates the CHM file, but when I click on a topic, nothing happens. The topics don’t open at all. The TOC books do, but not topics. I do get a compiling warning  “The size of the stop file has to be limited in 512 bytes.” I have no clue what the stop file is. Did a quick search but didn’t find anything useful other than another user a few years ago who had the same issue and same warning. Unfortunately, I did not see resolution posted. Any help would be greatly appreciated! Thank you.