...
Occurs in Rapid Clipse 2.3.x for projects that were already updated to version 3.0.0 RapidClipse Frameworks.
This error is due to a project configuration that no longer matches the new framework version.
The RapidClipse Framework Versions 1.3.0 and early versions of 3.0.0-SNAPSHOT work with EhCache 2, the project configuration is adapted to that, including entries in the persistence.xml.
...