What steps will reproduce the problem? 1. Create an ini-file on disk with a ini-section right at the beginning of the file. Save it as UTF-8 with BOM. 2. Create an nsis script which modifies the first ini-section with WriteINIStr. 3. run the nsis-script.

What is the expected output? What do you see instead? I expect to have a valid ini-file with a ini-section that occurs only once. But the section occurs twice.

What version of the product are you using? On what operating system? NSIS Version 2.46 on Win XP, Win 7 (32 and 64 Bit)

Please provide any additional information below. I think the problem is, that nsis reads the ini-file as ASCII and so reads the first line with BOM and section thus it is not recognized as the requested section-name. Therefor it creates a new section. The problem does not occur if the first line is empty!

Please try saving your INI file as UTF16LE instead. This is a Windows API issue.