Postgres INSERT returning 'invalid input syntax' for json - sql

Question

Problem: Attempting to insert a JSON string into a Postgres table column of json datatype intermittently returns this error for some record insertion attempts but not others.
I confirmed using multiple third party 'JSON validator' apps that the JSON I am inserting is indeed valid, and I have confirmed that any single ' quote characters have been escaped with the double '' technique, and the issue persists.
What are some additional troubleshooting steps to consider?
Here is a scrubbed sample JSON I have attempted:
{"id": "jf4ba72kFNQ","publishedAt": "2012-09-02T06:07:28Z","channelId": "UCrbUQCaozffv1soNdfDROXQ","title": "Scout vs. Witch: a tale of boy meets ghoul (Official Version)","tags": ["L4D","TF2","SFM","animation","zombies","Valve","video game"],"description": "Howdy folks (he''s alive!). I made a new SFM video (October 2015), called \"Nick in a Hotel Room\". Please check it out: https://www.youtube.com/watch?v=FOCTgwBIun0\n\nAlso check out some early behind the scenes of Scout vs. Witch:\nhttps://www.youtube.com/watch?v=73tQEBgD09I\n\nYou can find links to my stuff on my website: http://nailbiter.net\n\n-----\n\nhey gang,\nI''m the animator who made this cartoon. Hope you like it.\n\nThis is my little mash-up of a bunch of stuff I like. What happens when the Scout from Valve''s Team Fortress 2 video-game walks into the wrong neighborhood (Left 4 Dead). Hilarity (and a bodycount) ensues. It was created using Source Film Maker (for all the dialog stuff and the montage at the beginning), and with TF2/Source SDK for the entire 300 alley-run sequence. I had already completed that part before SFM was released. The big zombie horde scenes and a couple others were shot in Left 4 Dead. I hope you get a kick out of it.\n\nStuff I did:\nI animated all of the characters (using Maya) except for the big crowd scenes and parts of the headcrab zombie (the crawling and the legs). The faces in the dialog scenes were animated in SFM.\n\nAlso did additional mapping, particles, motion graphics, zombie maya rigging, and created blendshapes for the Witch''s face to enable her to talk/emote. I didn''t do a full set, just the phonemes I needed for this performance. Inspiration for her performance was based on Meg Mucklebones (if you''ve ever seen Legend) mixed with the demon ladies in Army of Darkness. I have a feeling Valve had seen those movies too when they designed her..\n\nthanks for watching."}

Answer 1

I am answering this question by enumerating all the other troubleshooting steps I have found so far, either 'working knowledge' that 'field workers' will have, or a little more obscure (or buried in postgres docs which, while thorough, are esoteric) insights I have found thru my own trial & error
Steps
Make sure you have escaped any single quote ' characters by double-escaping with like ''
Make sure your JSON string is actually a single line string - JSON is very easy to copy as a multiline string, and postgres JSON columns will not accept this (easy as hitting backspace on any newline)
Most obscure I've found: even when encapsulated in a JSON string field, the ? question mark weirdly enough breaks the JSON syntax for postgres. Something like {"url": "myurl.com?queryParam=someId"} will return as invalid. Solve this by escaping the question mark like: {"url": "myurl.com\?queryParam=someId"}