Please look at my comments to https://tex.stackexchange.com/a/13716/30810:
They cannot be copied and compiled because there are zero-width non-joiners and and zero-width spaces (
‌​ in HTML source code) inserted in the code snippets. (You also see weird behavior in some text editors when you copy and paste this.) After the first two times, I thought this might have been the result of copy-and-pasting this from somewhere, so the third time, I typed the whole comment without pasting from anywhere. Interestingly, these things appear mid-word in different places. Is this a browser bug (Windows 10, Chrome, 58.0.3029.110), or is this a results os TeX.SX processing?