Talend: fix "Plugin X or one of its dependencies could not be resolved"

On Talend, you can have the following exception:

"An error occurred (java.lang.Exception: [ERROR] Plugin X or one of its dependencies could not be resolved: Cannot access central (https://repo1.maven.org/maven2/) in offline mode and the artifact X has not been downloaded from it before"

This error can occur when jar files are missing from the Talend environment for the requested action (build, run, publish, guess schema ...). To correct the problem, use the following method:

• Go to the Window menu then choose Preferences
• On the right side, click on Maven
  
• Uncheck the Offline option (checked by default on a new installation of Talend) then click on Apply and close

Retry the failed operation. Talend will now download the missing jar files.