Exception in thread "main" cucumber.runtime.CucumberException: No backends were found
This error is thrown when no 'backends' are found on the classpath. There is a 'backend' for each supported language (e.g. cucumber-java, cucumber-groovy etc.)
It's probably a classpath error, although if cucumber-core and cucumber-java are in the same location that does seem strange.
Make sure you're adding below dependencies for Maven project:
You can replace version to the latest or the required version:
<dependency>
<groupId>info.cukes</groupId>
<artifactId>cucumber-java</artifactId>
<version>1.2.0</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>info.cukes</groupId>
<artifactId>cucumber-junit</artifactId>
<version>1.2.0</version>
</dependency>