You'll get that message when your browser doesn't know what to do with the data that is being returned to it. Try contentType="text/html".
Also, lose the <META> tag. It's not only redundant (since you indicated contentType on the <%@ page directive), it's positively dangerous. I just spent 3 weeks going stark raving mad because forms being submitted weren't providing the control values. Some clown had coded a META tag that redefined the content type.
Plus, I don't even guarantee that META content type will work properly on all browsers or all versions of IE or even individual versions of IE with different DOCTYPES (which I like to call their "select-a-bug" feature).
Blitzlügen - Lies or information broadcast, but when called out the broadcaster does little or nothing is done to correct them, thus allowing those who wish to believe to accept them as truth.
Lügensturm - A barrage of Blitzlügen fired in such quick succession that it is essentially impossible to correct them all.