[Eclipse]安装过程遇到 Cannot continue the operation. There is another install operation in progress.

本人在使用eclipse安装插件时，遇到：

1.安装时提示Cannot continue the operation. There is another install operation in progress.

如图，原因是eclipse软件正在安装另一个插件。在eclipse右下角，会显示进度，但是往往会被人忽略。