I hear you -- my guess is it's that my IP address is cookied somewhere in a session in a load balancer, making me "sticky" to whichever node isn't working right. I've saved off my reply to a notepad and will come back to it tomorrow, in theory after any sessions have sticky timed out then see from there...

@hchc thank you for the hint! It turns out it's the combination of "slash-etc-slash" with the second slash being the key - spaces around it don't matter, you cannot seem to have the string of those 4 characters in direct order either alone or with other content, nor in code blocks. Kinda cumbersome, being one of the key/main directories in every UNIX/Linux based system but I suppose the forum team has their reasons.

EDIT: as I type you updated too, thanks kind stranger - we're on the same wavelength, exactly what I found