Some users reported that they fixed the Steam not downloading DLC issue by restarting Steam client and Windows PC. Now, the selected DLC will start downloading and installing automatically. In the pop-up window, tick the checkbox of Enabled under the DLC that you want to install. Scroll down and click on Manage my DLC at the left side of the screen. Launch your Steam client, and then go to the Library tab and select the game that you want to install DLC. If you encounter the Steam DLC not installing issue during the downloading process, you can delete it first and then follow the steps below to reinstall DLC properly. After analyzing several posts and user reports, here we explore several effective troubleshooting methods. Sometimes, however, you may encounter the Steam DLC not installed issue during the process.
Open the game properties from Steam Library and go to the DLC tab where you can view your just installed DLC from Steam Store. You can also view the installed DLC from the game properties window. Tip: If you don’t see the installed DLC, you can choose Library from the top menu and download it.