I used the TopStyle HTML editor for a couple years with XP and it ran fine. So I tried Win8 Pro 64's compatability mode for XP SP2 and for SP3 but TopStyle throws a fp divide by zero error frequently. Some files can be edited without a problem but then may suddenly produce this error, other files always produce this error. Mainly the error arises when attempting to preview the file being edited.

The information provided shows the error is from mshtml.dll so I poked around and found a discussion of a similar problem here: delphi - How to debug division by zero exception in Internet Explorer? - Stack Overflow

Is there a way to suppress the error in this admittedly old program?