Well after doing some more searching I discovered the error may be related to other issues as invalid keystores, passwords etc.
I then remembered that I had set two VM arguments for when I was testing SSL for my network connectivity.
I removed the following VM arguments to fix the problem:
-Djavax.net.ssl.keyStore=mySrvKeystore -Djavax.net.ssl.keyStorePassword=123456
Note: this keystore no longer exists so that's probably why the Exception.