Looking at the size and doing a few tests suggests it might be due to us still using signed 32 bits integers for holding positions and alike. Maybe even in Scintilla, that might require a specific define to use 64bits positions. This would mean trouble when the file size is greater than `(1 << 31) - 1`, which your file definitely is. I'll try and dig a little more, but it might be far from trivial to fix ATM :confused: