There are possibilities.
If you are using maven to build dependencies, there are possibilities that one of your JAR file is not download. So, try to remove .m2 folder and build your dependencies again.
Also, in your pom.xml file, remove below lines.
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-api</artifactId>
<version>2.42.2</version>
<scope>test</scope>
</dependency>
As appium 1.3.0 is dependent of Selenium 2.46.0.
If you have added your libraries manually, you should try verifying if you have missed any library to be added.
Hope that helps!