1031 - Unknown char '%c' following '%s' directive. (Expected '%c').

Description
Following a recognized directive, an unexpected character was encountered. Expected characters vary depending on the directive.
Example
Config:
#include(
Output:
c:\test\fbuild.bff(1):(9) FASTBuild Error #1031 - Unknown char '(' following 'include' directive. (Expected '"'). #include( ^ \--here
Fix:
#include "subdir/fbuild.bff"