WARNING: Illegal reflective access

i,does any one knows what this means"serviio.sh[16753]: WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/opt/serviio-2.0/lib/xstream.jar) to field java
",this sentence appears on my servvio status!!???what is the meaning,is there a solution!???

[atc98092]

You're seeing this in the Serviio console? We've seen some strange messages and failures of the console web pages when upgrading a Serviio version, in particular when upgrading to 2.0. In every case of those that I've heard, clearing your browser cache eliminates the errors. It's usually due to cached code that has changed from one version to another.