找到出錯的jar包文件位置，刪掉_maven.repositories文件（或用文本編輯器打開，將“>main=”改為“>=”，即刪除main，當然main也可能是其他值），然后update project。
_maven.repositories簡介：
_maven.repositories hold the information about the origin of the artefacts. Maven tries to update your jar from the old location (as saved in _maven.repositories) and fails. The presumtion here is that the same aftifact on a different remote repository might be different.