I found one of reasons to this bug and paste it on GitHub, so now you should wait when devs fix that, or:
Open enigma-dev\Compilers\Windows\gcc.ey in Notepad++/ any other text editor which show lines
change line 15 to this:
cxxflags: -std=c++11 -I/mingw32/lib/libffi-3.2.1/include -I/mingw64/lib/libffi-3.2.1/include -I../Additional/i686-w64-mingw32/include
[
https://github.com/enigma-dev/enigma-dev/issues/1734 ]