I suspect Tim is correct and it's because of the missing quotes.
Whilst Applets should work the same on all platforms the html that kicks off the Applet is read and processed by the browser and it may be that the browser you are using doesn't understand the param tag with missing quotes whereas Tim's browser has made some correct assumptions about what you intended to write. Can you make the changes he suggested and let us know if that has fixed the problem.
BTW Tim is also correct about Applets being obsolete, I suggest you don't spend too much time learning how to write code for them.
It never hurts to use well-formed HTML. And since your error messages from the original post tell me that your applet parameters are being ignored, it might be that using sloppy HTML is a problem. It might also be that something else is causing Netbeans to fail to notice the parameters.