I created a symbol for my build called "NO_COMPLEX_ALARMS" to exclude code from one of my projects, but it doesn't seem to work. I've used it may times before using the standard symbols such as DEBUG, but not my own symbols.
I don’t see it. You defined NO_COMPLEX_ALARMS and the code is included as expected. The error message does not relate to your conditional, unless there is more to it then you are showing in the screen shots