When adding a new include path via Properties > C/C++ General > Paths and Symbols > Includes, the ‘Add directory or path’ dialogue has the options to add to all configurations and all languages;
But when editing an existing include path in the same place, the ‘Change directory or path’ dialogue has no such options! 
So changes have to be applied individually to each language - which is laborious, tedious and, thus, error-prone.
Related: https://forum.sierrawireless.com/t/suggest-improve-handling-of-project-errors/4328/5