An internal error occurred during: "Importing Maven projects"

Hello All,































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































I'm new to maven. when I tried to import an existing maven project I get the following error:

An internal error occurred during: "Importing Maven projects".































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































org/sonatype/aether/resolution/ArtifactResolutionException

could you plz help me in solving this problem?