Okay @didate! Thank you for sending the response (which is exactly the same as the screenshot in your topic post above)! Then maybe the way to go is to understand the request. Are you facing this issue every time you try to download (.xls, .csv) or only for this request? Can you try .json for this request do you still face an issue? Thanks!
@didate also is it possible to try a similar request like this one on play.dhis2.org?
From your previous topics, these are your system settings and configurations (reference for experts answering):