When I switch a Web Project in RAD from Targeted Runtime WebSphere 6.1 to 8.5, all of a sudden I get compilation errors that just the basic java. packages cannot be found. Despite seeing them in the included "WebSphere Application Server V8.5 JRE" library.
The type java.util.Map cannot be resolved. It is indirectly referenced from required .class files
When I switch back to WebSphere 6.1 Targeted Runtime (and revert the automatically-changed Project Facets to appropriate versions too), compilation works again.
Any ideas how to resolve or debug?