Description Resource Path Location Type Unknown Unknown Unknown org.eclipse.core.internal.resources.Marker is not of a displayable type

是访问限制报错.

方法一:
全局属性Project>preferences>java>Compiler>Errors/Warnings>把右侧的【Deprecated and restricted API>Forbidden reference的Error】置为【Warning】.

方法二(终极方法:)
项目属性preferences>java build path>把右侧【libraries中的JRE System Library】删除重新导入.