Since comments are ignored by the compiler, it's difficult to believe that they are the cause of the problem.
The assignment of " (an escaped double quote) may be a legal assignment, but what value is actually placed in x?
It's likely that the invalid value in x was causing problems that didn't show up until x got put in a memory location that some code is overwriting, due to writing out-of-bounds, or mis-reading (again due to an out-of-bounds situation).