Happy New Year!!!
Indeed, AM limit for DVD is 99 chapter points, for Blu-ray 999. So I'm surprised it cannot handle 80+ files. You do not have CUE files loaded next to one or more or your files such that you go above 99? (since every CUE point is counted as a chapter point).
I will need to get a bit more information in order to help you out. Run again your process and then go to Application/Show Logfile and PM me any issues you'll see there in that log file. If possible, save your project and PM me that file as well. We will sort it out, no problem
![Smile :)](./images/smilies/icon_e_smile.gif)