版本说明（v3.0.1 mod 5）：
1.Bug修正：如果在生成前没有指定输出目录，那么在生成时程序会让你选择输出目录，在选择之后程序会抛出一个异常导致转换无法继续。
2.改进/变化：当正在执行游戏包生成时禁止拖放操作。
English version
Release Note(v3.0.1 mod 5):
1.issue fixed: app will throw an exception if you didn't specify the output directory before building, after you select output directory during building process. this will abort the building process.
2.change: disable the drag & drop operation during building.