What does the Java Applet security warning “JAR file manifest does not contain the Permissions attribute”mean?

Question

I have a Java Applet which needs access to the local filesystem of the client. I have created a simple certificate for my own (it is NOT certified by Verisign,Commodo, ...). I s

Answer 1

You don't need to buy a certificate, just fix the manifest file.

Add this line:

permissions: all-permissions

Or this line if you need only limited access:

permissions: sandbox