Vimaladevi,To run a Java class from the command line, you need to either be in the directory containing the compiled .class files,or have those files in your classpath.I'm not an Eclipse user, so I don't know where Eclipse places the .class files. But if I were to take a guess—you might tryrunning the command from inside the 'test' directory instead of the 'test/ec' directory?SiggyOn Sun, Jan 31, 2016 at 1:22 PM, Vimaladevi M <[log in to unmask]> wrote:Hi Mr. SiggyThanks for your reply.i imported ecj\ec files into a new project in eclipse.when i tried to run it, i got the below error in eclipse console and command prompt too."Error: Could not find or load main class ec.Evolve"but i was able to clear this error now. for this what i did was deleted ".metadata" folder and created a new project again and imported the ecj\ec classes. i m able to run the tutorial1 using eclipse. but the problem still persists if i run through command prompt. please see the below screenshot.On Sun, Jan 31, 2016 at 8:52 PM, Eric 'Siggy' Scott <[log in to unmask]> wrote:Vimaladevi,Can you give us some more information? How exactly are you trying to run it?Siggy--On Sun, Jan 31, 2016 at 1:48 AM, Vimaladevi M <[log in to unmask]> wrote:Hi AllI am trying to ECJ for my research work.I get the following error when I try to run the tutorial programs."Error: Could not find or load main class ec.Evolve"I have tried setting path variables and I am using Eclipse mars versionPlease help me out.--Ph.D student in Computer Science, George Mason UniversityCFO and Web Director, Journal of Mason Graduate Research----Ph.D student in Computer Science, George Mason UniversityCFO and Web Director, Journal of Mason Graduate Research