Solution : https://service.sap.com/sap/support/notes/951105 (SAP Service marketplace login required)
Key words :
including german umlauts, view -> encoding -> unicode, terms utf-8 reason, html output, data overviews, displayed correctly, smart forms, page breaks, browser menu, program error
Related Notes :
| 948212 | WebForms: the format border is missing in the HTML display |