Solution : https://service.sap.com/sap/support/notes/554889 (SAP Service marketplace login required)
Key words :
additional blank characters, blank character reason, double-byte character, additional blank character, long line format ' = ', format correctly, line breaks, importing note 513871, html conversion, sapscript texts
Related Notes :
| 513871 | FORMAT_TEXTLINES_DBCS is formatted incorrectly |