Appears to be a Beautifier problem

Editing any file and then saving causes a beautifier error which terminates the beautifier pass.
Update #1: Only some files, not ANY file.
Update #2: It appears as if the problem occurs with indented preprocessor statements. For example:
#ifdef DUE
#define xxxx
#else
#define yyyyy
#endif

Though it doesn’t happen for all.
end-of-update-#2

Stack Trace

OS X 10.14.1
Atom-Beautify 0.33.04
PlatformIO 1.0.6 3.6.2b5