Run uploaded java applet

I uploaded my java applet and an index.html file with a correct reference. But when I load my webpage I get an errormessage"
"Incompatible magic value 1013478509 in class file blackjack5"


This is the URL of the webpage: [Moderator edit: link removed]


Anyone know what this means?
Does the webserver require specific Java functionality? Or is this only neccesary on the client computer?

That error can occur when the .class file is invalid. Check that the class file is OK.

That was it, my file was not sent over correct, because the free webserver did not allow .class files

Try putting the class file in a zip file and use the archive= attribute