Solution : https://service.sap.com/sap/support/notes/537650 (SAP Service marketplace login required)
Key words : 
path start->settings->system control->system->advanced ->environment variables->user variables2, user logon scripts, users <sid>adm, directory /home/<userame>, start sapinst, required environment variable, terms ifx_7xkeystyle reason, ifx_7xkeystyle environment variable, environment variable ifx_7xkeystyle, variable ifx_7xkeystyle=1 locally
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