If you've purchased The Outer Worlds on the Microsoft Store or gained access through Xbox Game Pass for PC, there are a few reasons that could explain why you're unable to access your DLCs.
The DLCs are not properly installed.
Head over to My Library, and in the Installed page, make sure that your DLCs are showing in the list. If they are not, open the Ready to Install page and install the DLCs.
Your installation of The Outer Worlds may be damaged or incomplete.
Uninstall the game by clicking on the Windows button, click on Settings, Apps, and then open the Apps & features page.
Next, from "My Library" on the Microsoft Store, open the Ready to Install page and install both The Outer Worlds and the DLCs.
Your Microsoft Store account is connected to too many devices.
If you've connected your account to 10 or more devices, you may be unable to access certain products, like your DLCs, on your computer. To resolve this, you'll need to remove a number of devices from your account.
If you need assistance removing some devices from your account, click here for instructions.