I checked out a Java project from SVN in eclipse and realized that it requires Java 8 because it uses lambdas etc. I installed the eclipse addon for Java 8 and restarted ecl
I had the similar problem with eclipse kepler.I have followed these steps to resolve it
for reference, refer this link http://techno-terminal.blogspot.in/2016/05/jdk-18-compiler-compliance-is-not.html