Ma Lin <malincns@163.com> added the comment: I suffered this problem more than one years. Here is a solution, before compiling the chm, modify like this: --- D:\Python-3.7.1\Doc\build\htmlhelp\python371.hhp Sun Dec 02 13:12:37 2018 +++ D:\fix_crash\python371.hhp Sun Dec 02 13:05:57 2018 @@ -1,6 +1,6 @@ [OPTIONS] Binary TOC=No -Binary Index=No +Binary Index=Yes Compiled file=python371.chm Contents file=python371.hhc Default Window=python371 The chm will generate a binary file python371.chw in the same folder when first opened. No longer crash, but duplicated entries don't show Title anymore, see the attached picture. ---------- nosy: +Ma Lin Added file: https://bugs.python.org/file47967/binary_index.png _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue35228> _______________________________________