You could probably replace it with a "known safe" DLL and be just fine. SciLexer.dll is for Scintilla, which is a fancy GUI widget for code. The lexer is part

You could probably replace it with a "known safe" DLL and be just fine. SciLexer.dll is for Scintilla, which is a fancy GUI widget for code. The lexer is part of the parser that determines the things like what code to highlight, scope folding, etc.