ringram2077:
I assume the compiler does not pick this up as an error.
That isn't it. The compiler would certainly have picked it up. However, the IDE crashed before it got as far as invoking the compiler.
The Arduino IDE contains its own attempt at a code parser and analyser which is supposed to generate function prototypes for you. That's a bad idea IMO and seems to be motivated by a misguided and unsuccessful attempt to make C++ look like Java. Unfortunately the people who implemented that didn't do a very good job and the result is that it routinely messes up your code and sometimes even crashes. The way to resolve the problem is to simplify your code far enough for the Arduino IDE to cope with it. In this case, since you intended that line to be a comment, you should be able to simply comment it out.
I think you'll find that the problem in this case is the un-matched double quote which might cause the IDE to treat the following text as an extremely long string literal. I've seen other cases where the IDE blows up when it encountered long strings.