Can't make Spark 2.7.2 to work on Ubuntu 14.04 LTS x64

I followed this guide http://www.2daygeek.com/how-to-install-spark-im-client-in-ubuntu-14-04/ until step 10a

I downloaded https://www.igniterealtime.org/downloadServlet?filename=spark/spark_2_7_2.tar.gz

On step 9 I didn't get anything on the file error.log Yet I proceeded to install the libraries hoping to get it to work However I couldn't launched from the desktop, so I run:

$ /opt/spark/Spark

And get:

Error: Could not find or load main class com.install4j.runtime.launcher.Launcher

I read here Installing Spark IM Client in Ubuntu Linux that it may be a Java Virtual Machine issue so I'm putting my version of java:

$ java -version

java version "1.6.0_24"

Java(TM) SE Runtime Environment (build 1.6.0_24-b07)

Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)

Any help would be appreciated

Message was edited by: Juan Carlos Fixing a typo