RoboHelp 10 is installed on my machine. When I generate the WebHelp output, the output file does not open in Chrome.
Going back a few years all the authoring tools had problems with browser changes. These were fixed by patches and later releases.
That seems to have settled down now but RoboHelp 10 dates back to that era. Check you have the updates and if it still fails, I think your only option would be to upgrade.
Could be worth a call to Support to see if they have any fixes but I doubt it.
See www.grainge.org for free RoboHelp and Authoring information.
Shoot me a PM - I have a folder of files that I dump into my output after it's generated to make it <currently> work for all browsers that I could zip up & send you.