Error 3 appears in the Content Manager when you trying to install a DLC but are missing entitlements.
To fix this issue, you will need to contact support.
1. Click on "Submit a request" in the top right corner of this page.
2. In the drop-down menu "How can we help", select "I have an issue with a purchase".
3. Under "I'm having the following problem" select from the drop-down menu select Content Manager "Error 3"
In the description, don't forget to include the name of the DLC that you're unable to install. Our team will manually redeem the entitlements as soon as possible.