Script error when calling context-sensitive help

We are using RoboHelp 2015 and compiling a WebHelp project to be installed locally and called from our application. The help is accessed fine when the user selects the Help menu but when they click F1, they get the following script error. If I click Yes, the help seems to work fine but the error but returns if I close the help window and click F1 on the same or another window. This has worked fine in the past so we are unsure if it is due to a change in RoboHelp with 2015 or something else. Our developers have not changed how they are making the help call.

I would appreciate any guidance you could provide.

Thank you,

Nita