Solution : https://service.sap.com/sap/support/notes/616914 (SAP Service marketplace login required)
Key words :
prerequisites internal browser optimizations, patch level 25its release 620, terms sap gui, internet explorer solution, patch level 4, browser window, patch levels, close reason, javascript code, set ~disconnectonclose
Related Notes :
638165 | SAPGUI for HTML: ~disconnectonclose not default |