very simple to reproduce:
just create a scintilla window, enter a few lines of text (at least one line). If Hidelines(lineNr,lineNr) is called, it behaves normally except for lineNr=0 which crashes the app.
I am using a 1.75
I don't understand how something so big has not been already corrected. This is quite an annoying bug...
Ludovic Aubert at email@example.com