Just upgraded from 2016 -> 2021 on production and everything worked! about 4 tickets of things we knew already would kerplode but other than having to install the QoQ hotfix its going rather smoothly. Fingers crossed it continues that way

@chris_hopkins We're getting ready to do the same upgrade. Any advice / suggestions / warnings?

1. apply the QoQ hotfix (email adobe for it or dig it out of the hotfix section of downloads page) 2. some CFinput stuff for autosuggests got killed off (we have some super old stuff in some places) 3. there are some issues with serializeJSON() converting yes/no to true/false that got fixed post 2016 that can trip things up 4. Dateformat issues, multiple workarounds - https://helpx.adobe.com/coldfusion/kb/dateformat-function-coldfusion-2021.html 5. super random edge case that i am sure wont apply but we had to work around - https://tracker.adobe.com/#/view/CF-4212005 We have not transferred all our servers over yet but the first two seem to have gone swimmingly once we fixed the above