@Bob99: Everything seems like it posted correctly... I'm not sure how to interpret the defaultPrefs.txt content, the developer (Twinbee) will need to do that.
I am curious about how you files are grouped into one folder... Are you using TotalCommander to display all the contents into one flat view, or are they actually all *in* one folder? When I unzip mine, I get the main OpalCal_Demo folder with the img folder inside
but then, inside the img folder I have only PNGs and an ICO.
is your img folder empty??
Maybe move those PNGs and the ICO into that folder....
Also, is it possible that you have some advanced setting on your unpacker plugin that is putting everything into one folder, rather than reserving the folder hierarchy of the zip? If so, Maybe try just downloading it to your Desktop, then Right-click and use the generic Windows extractor(?)
EDIT: Okay that's good! Now I'm curious what file manager you use though