Downloaded and played fine, now says I need to redeem code but codes used???

Well, I can see you definitely own the game, and it shows up correctly over here. Here are a few more ideas to try:

Make sure your library is set back to Show: "All Games" and Platform: "All Platforms" - maybe Platform got switched to Mac by accident somehow?

Does your Sims 4 Create A Sim Demo game tile still show up in your library?

Check your Origin version: "Help" -> About (this should be 9.4.22.2815)

Could you take a screenshot of your games library and post it on an image sharing site?

Last idea... submit an Origin Error Report and I'll take a look at the diagnostic info to see if I can figure out what's happening:

- Click on "Help" then 'Origin Error Reporter'

- For 'Type of Error' choose "My Games Library"

- Leave 'Customer Support Ticket Number' blank.

- Type a quick description of the problem, e.g. Sims 4 isn't showing up in my library anymore

- Check the box if you agree (you can read what information we will collect here http://download.dm.origin.com/oer/en_US.html)

- Click "Send Report"

- Finally, copy your Report ID and paste it into a reply to this message so that I can easily find your report.