A hint for the “Object foo is not a known entity type” errors from Glassfish

As a JavaEE-codemonkey you have perhaps noticed this error:

java.lang.IllegalArgumentException: Object: Ting@193c227 is not a known entity type.

This will occur when you have redeployed an app f.ex through Eclipse to Glassfish, the Glassfish server has not quite understood that it`s time to update its version, so what you need to do then is to simply restart the server (or domain).