当我试图在同一版本中第二次将项目部署到APP引擎时，它说：
Unable to update app: Error posting to URL: https://appengine.google.com/api/appversion/create?app_id=adaptivecourse&version=122&
409 Conflict
Another transaction by user jyothirmayi.prasad is already in progress for app: s~adaptivecourse, version: 122. That user can undo the transaction with "appcfg rollback".
我无法理解背后的原因 所以，我所能做的就是将项目部署到另一个版本 实际发生了什么？