錯誤信息:
Deployment is out of date due to changes in the underlying project contents. You'll need to manually 'Redeploy' the project to update the deployed archive.
Missing web.xml deployment descriptor in WEB-INF folder
Run As → Maven clean → Maven install → 伺服器右鍵 Clean → Publish。src/main/webapp/WEB-INF/web.xml 必須存在(Servlet 3.0+ 可選,但 MyEclipse 可能強制檢查)。若缺失,新建標準 web.xml 或在項目屬性中關閉驗證。Deployment Assembly 包含 src/main/webapp → /、target/classes → /WEB-INF/classes 等。多數情況下是 Maven 構建產物未同步到部署目錄,執行 Maven install 並手動重新發布即可。