MyEclipse running Java error: Could not find the main class:test.program would exit (import project)

No problems with running your own new project.
But I imported a project that someone had written long ago, and then run would bounce the box could not find the main Class:test.program will exit

Make sure the Java compiler and JRE versions are consistent
Right click on Project--->>>preference-->>>java compiler view compiler version
Right-click the project--->>>build path--->>>configure build path--->>>libraries-->>jre system Library View JRE version

Can be modified into a sample

MyEclipse running Java error: Could not find the main class:test.program would exit (import project)