对于任何来这里的人:

我让它在不同的环境下工作.代替Flex，我按照配置

I got it working using a different environment. Instead of flex, I changed the environment to standard with java8 following the configuration explained here. The weird thing is that now the app consumes more memory than before (about 300Mb), but now it's working without issues. Note that app.yaml is not used anymore, and now the application is deployed as a WAR.

谢谢