Sims 4 farm items won't show other than a red X in build mode.

@xion123456xxx  This isn't an issue with the CD key, which either works or doesn't.  In your case, the pack is in your account and the EA App lets you install it, so that's all that matters.

Instead, please try playing in a clean user folder.  Move the entire Sims 4 folder to the desktop, and when you launch the game, a clean folder will spawn with no content.  Your saves and other content won't load, but that's fine and can be addressed later.  For now, just start a new save and see whether the problem is still present.

If it is, please do a clean uninstall of Sims 4 and the EA App:

• Put aside your Sims 4 folder in Documents\Electronic Arts and rename it to something that doesn't include the words "Sims 4."
• Download Revo Uninstaller (the free version is fine) from here.
• Launch Revo, select Sims 4 from the list, and click Uninstall.
• Once the game is uninstalled, select "Moderate" under "scanning modes," and click Scan.
• Review the list, in case there's something you want to save; otherwise, click Select All, and then Delete.
• Close Revo, and restart your computer.

Uninstall the EA App with Revo as well.  The process is the same, except Revo will also find some registry entries that you should delete.  Restart again when you're done.

Install the EA App, then create a new folder into which you'll install Sims 4.  The folder should be on the root level of the drive of your choice, for example C:\Games is fine, but not C:\Program Files\Games.