Unable to upload text ads

Steps:
--------
1. Downloaded the latest aml-ad-load-cli-1.0.4-RC1-jar-with-dependencies.jar file.
2. Copied to monman server.
3. Used old core content builds.
4. Executed the following script.

java -jar aml-ad-load-cli-1.0.4-RC1-jar-with-dependencies.jar -d /home/amlops/etads_1/ -h aq-qa2-mysql1:3306 -l 2 -uspike

Expected: Script should execute successfully and upload all the text ads.

Actual: Throwing java.lang.UnsupportedClassVersionError exception.

[root@aml-qa7-monman1 business_taxonomy]# java -jar aml-ad-load-cli-1.0.4-RC1-jar-with-dependencies.jar -d /home/amlops/etads_1/ -h aq-qa2-mysql1:3306 -l 2 -uspike
Exception in thread "main" java.lang.UnsupportedClassVersionError: com/admaxlocal/content/AdLoader : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:268)
Could not find the main class: com.admaxlocal.content.AdLoader. Program will exit.