subModal() Failing?

I am using Toolbook 11.5 with Patch 4 installed. I'm working on some older projects that were produced with Toolbook 11.5 and an earlier version of the PowerPac where this function worked perfectly. In an attempt to get it to work again, I just updated the PowerPac to 12.904.1.
I am using a relative path to a folder full of html files and when I examine the exported content, the html files are where they should be. When I publish the book and test my menus, anything that uses the subModal() function is failing.
Any suggestions on how I can troubleshoot this issue so I can get my project back on schedule?
Thanks,
Pete
I am using a relative path to a folder full of html files and when I examine the exported content, the html files are where they should be. When I publish the book and test my menus, anything that uses the subModal() function is failing.
Any suggestions on how I can troubleshoot this issue so I can get my project back on schedule?
Thanks,
Pete