hello I do if you asked me I typed javac
From your error message, I can guess that you wanted to install oracle-java-8 and for any reason that installation wasn't successful or half-broken now. So, I suggest installing these to run scala-2.11.6 on Ubuntu 16.04.
First install java
sudo apt install openjdk-8-jdk
Then install scala
sudo apt install scala
The repository for Ubuntu 16.04 has scala verson 2.11.6 and I've installed it and tested without any problem.
If you face further problem, edit your question describing how the answer didn't help.
First, install JDK
sudo apt install default-jdk
sudo apt-get install scala