Consequently, you cannot use more than one Outline on a page at a time. If you try opening the page in FP you will not see the applet, but instead a set of indented lists which you can directly edit. Hopefully this will make you life easier. You set the width and height to be large enough to display the outline tree when it is fully expanded. I'd suggest you put the class files in the same directory as the page on which it will appear.
Some web browsers have trouble opening applets straight from a hard disk.
I have noticed this happen with Internet Explorer 3 and Netscape 4. Class files are binary files, just like image files are. You should transfer them in the same way that you transfer image files. This is a very common problem. Your transfer program has changed the name.