Catch errors caused by using Java 6 jar files in Java 5.

h2/src/main/org/h2/util/ClassUtils.java

@@ -85,6 +85,8 @@ public class ClassUtils {
             } catch (Exception e2) {
                 throw Message.getSQLException(ErrorCode.CLASS_NOT_FOUND_1, e, className);
             }
+        } catch (UnsupportedClassVersionError e) {
+            throw Message.getSQLException(ErrorCode.GENERAL_ERROR_1, e, className);
         } catch (NoClassDefFoundError e) {
             throw Message.getSQLException(ErrorCode.CLASS_NOT_FOUND_1, e, className);
         }