It would help, if you post the text next to the breakpoint, it usually explains what happened 
In this case I guess, that the path was not accepted. On windows, you use backslashes. But because they have a special meaning in C/C++ code, you have to quote them, that means preceding the backquote with a backquote.
Long story short, try:
File input ("C:\\bongo.wav");
And for building filenames later use File::getSpecialLocation() and from there File::getChildFile(), that way you wonāt need to worry about slash or backslashes, and your code works on any plattform juce supportsā¦
To make it work on any plattform. Some systems have one tree, others have drives with lettersā¦
The JUCE-way is to start with a so called āspecial locationā, e.g.
File input = File::getSpecialLocation (File::userHomeDirectory).getChildFile ("bongo.wav");
There are a many different predefined locations, see File::SpecialLocationTypeā¦
Or you can work in the current directory:
File input = File::getCurrentWorkingDirectory().getChildFile ("bongo.wav");