Please, be considerate and check to see if a macro is defined before just haphazardly defining it! My Visual Studio projects, and no doubt many others’ VS projects, have _CRT_SECURE_NO_WARNINGS defined by default.
#ifndef _CRT_SECURE_NO_WARNINGS //This is really simple, no brainer stuff
#define _CRT_SECURE_NO_WARNINGS
#endif
I am really not sure how your dev team gets a public API like the VST3 sdk so notoriously warning prone (and error prone for those who treat warnings as errors).