Maven 'Could not resolve dependencies for project' / 'Failed to read artifact descriptor' / 'Could not transfer artifact': how do I diagnose and fix it?

Cause: Maven could not obtain a dependency or its POM from the local repository or the configured remote repositories. Typical reasons: a wrong groupId, artifactId or version; the artifact lives in a repository that is not configured for the project; no network access, or a required HTTP proxy or internal mirror is not set up; a corporate repository needs credentials; a corrupt or partial download in the local repository; or a transitive dependency has been removed upstream. Fix (best first): 1. Read the full message: it names the exact artifact coordinates and the repository ids Maven tried. Check the coordinates against the repository (typos and missing versions are the most common cause). 2. Run mvn -U to force a re-check of remote repositories (this also forces re-resolution of entries Maven cached as missing). 3. If it is a network or access problem, configure proxy, mirror and credentials in ${user.home}/.m2/settings.xml (the per-user settings file; server entries must use an id matching the repository id). Do not put passwords in the project pom.xml; Maven supports encrypted passwords. 4. If the artifact is not in Maven Central, add the correct repository in the pom or a settings profile. 5. If the local copy is corrupt, delete only that artifact's directory under ${user.home}/.m2/repository (default location) and build again. 6. Look at the dependency chain with mvn dependency:tree. If an upstream project dropped a transitive dependency you rely on, declare it directly and manage its version in dependencyManagement. Avoid system scope, which binds the build to one machine. Verify: mvn -U clean verify completes and mvn dependency:tree lists the previously missing artifact with a resolved version. Sources: https://maven.apache.org/guides/mini/guide-configuring-maven.html https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html