I am trying to launch Direwolf20's FTB pack from twitch, and the launcher crashes when opening

I am trying to launch Direwolf20's FTB pack from twitch, and the launcher crashes when opening. Also, It says Launcher version 1.6.84, which is not even a version according to the dropdown.
This shows in the updates tab.

javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative DNS name matching mcupdate.tumblr.com found.

Game output:
Exception in thread "main" java.lang.UnsupportedClassVersionError: joptsimple/OptionSpec : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)