Bad version number in. Class file solution

Org. springframework. Beans. Factory. beancreationexception: Error creating bean with name 'sessionfactory 'defined in servletcontext resource [/WEB-INF/classes/applicationcontext. xml]: Invocation of init method failed;
Nested exception is Java. Lang. unsupportedclassversionerror: bad version number in. Class file (unable to load class com. Manager. BSO. Students)

Today, myeclipse8.5 is faulty. If you copy data from another workspace to another workspace, Tomcat will not be started.

Solution: Java program bulid path, Tomcat JDK, javaprogram --- javacompiler are integrated in three versions. Here I chose jdk1.5, but the same error still occurs. Finally, install jdk1.6, the three versions are all changed to 1.6 to solve the problem. I still don't know why, so I wasted 2 hours.