Scala repl throws error

You might have to run it with JDK 7 or 6

remove the scala 2.9.2 using terminal

 sudo apt-get remove scala 

download the latest scala from scala website

Installation instruction are giving on this link

Either update to a newer scala version (2.10.3+) or downgrade java to java 6/7. As you have seen in the output, 2.9.2 was here long before java 8 was introduced (Copyright 2002-2011, LAMP/EPFL), so they don't work well together.

This duplicate question contains exact instructions on ubuntu's java downgrade.