Hi Euclides,

I suggest to open support ticket with OutSystems team as urgent because its a production environment. 

This may happened because of upgrading two lower environments and production version still old. If there is any availability for one more environment DS environment you can make it same version as production and deploy all you currently running applications to it then make it production one for time will be used until upgrade production server. Then start upgrading production server then deploy from QA to Production server and perform regression test to your applications on newly upgraded production server to make sure everything is working as expected after that return original production server to be main one and you can drop or upgrade DS server and keep it.

Why don't you upgrade the production environment? The problem is that you deploy a code base generated with a newer platform version to an older platform version. As long as you have the production environment not upgraded you can have these issues and you will have a hard time doing for example hotfixes.