Hi Alice,
EJS comes in two 'flavours': for those who want to create simulations in Java, and for those who prefer JavaScript and HTMl for it. I guess you chose the JavaScript version (well done, it is much more Web aware).
In this case, the JavaScript version could read files (ending in .ejs) of the other version, but you will have no HTMLView (which is what you are experiencing). This is normal and you should not open these files with your version. Instead, open the JavaScript examples, which end in .ejss.
Most demo examples are duplicated in Java and JavaScript, so you are in good grounds.
Hope this helped and thanks for using EJS.
Paco (author of EJS ;-) )