Inside your class you are making some sort of call that is classified as
a deprecated  command. I prime example of a deprecated command is the
Thread.stop() (and a host of other Thread messages).

Deprecation is a function or class that is going to be removed from Java
at some point in the future. Deprecation happens when it is discovered
after the fact that the concept behind an idea (like Thread.stop) isn't
the best idea in the world and a new idea that works in a different way
takes over.

A decent IDE should be able to warn you about deprecated commands, and
show you where they are