2616421 - How to determine and correct illegal XML character error?

The 'Export to excel' function of an ALV grid creates a corrupt xlsx file, which cannot be opened by Microsoft Excel. The error message is similar to the following example:

"Removed Part: /xl/sharedStrings.xml part with XML error.  (Strings) Illegal xml character. Line 1, column 393939.
Removed Records: Cell information from /xl/worksheets/sheet1.xml part"

Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.

• SAP NetWeaver
• SAP Web Application Server for SAP S/4HANA all versions
• Web Dynpro for ABAP

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Line 1, column 670550. , KBA , xml error. (strings) illegal xml charact , BC-SRV-ALV , SAP List Viewer , BC-WD-CMP-ALV-ABA , ALV for ABAP , How To