Unity3diy - Posts about Unity Asset Store, Tuts, Solutions, Errors

 Preprocessor directives must appear as the first non-whitespace character on a line Here are some solutions collected. 1. event, you must have a method with the same name declared in the code behind page like below, protected void #btnLogin_Click(object sender, EventArgs e) { } But in C# cs files, as the  error  explains preprocessor directives ( # ) must appear as the first non-whitespace character that's why the error happens. Solution would be to adhere to proper naming conventions. See  here . 2. Preprocessor directives start with  # . You have a trailing  #  in line 10. It looks like you use Visual Studio which should mark the line in red. Also the error should tell you which line looks wrong. Edit: You probably just opened the file in Visual Studio, which will not load any assemblies. Please open your C# project from Unity, right-click in the project explorer and choose "open C# project" or similar Honestly this post should be removed for low effort, a simple Goo