Fortnite CPU 100% and not rendering buildings issue can refer to the situation when Fortnite is not loading or stuck on loading screen. The issue can be frustrating, but you do not need to worry as you are able to fix Fortnite not loading issue.
The first method is to reinstall Fortnite in your computer. Since a lot of technical issues are able to be resolved by restarting, it never hurts to restart your device and then open Fortnite again to see if the method fixes the Fortnite not loading problem. In case the Fortnite still will not load, or stuck on the loading screen, you can try reinstalling your game and get the newest version.
The second one is to set your graphics settings to Low. If your game settings is set High, there is a possibility that your Fortnite is not loading, since the graphics settings are too much to load for your computer. So, you need to set it to Low.
The third one is to update your graphics card driver. The missimg or outdated drivers in your computer is able to cause Fortnite will not load, especially your graphics card driver and your network adapter driver. In this case, you need to verify that your graphics card drivers are up to date. There are two methods to update your drivers. The first one is manually update drivers. You are able to manually update it by downloading the newest version of your drivers from manufactures and installing it in your computer. This method needs time and computer skills. The second one is automatically update drivers. For those who do not have time of patience, you can do it automatically with a thing called Driver Easy. This one will automatically recognize your system and find the right drivers for it. You do not have to know exactly what system your computer is running and you do not have to risk downloading and installing the wrong driver.
The fourth one is to run Fortnite as administartor. Running your game this way is able to grant admin rights to run your game in your computer and this will hopefully fix Fortnite not loading problem. First of all, open File Explorer, and head to the folder where your Fortnite was installed. Then, right click on the Fortnite executable and choose Run as administrator. In the next step, please click Yes in order to verify the UAC. In case you are prompted to enter your admin account and password, then enter the information. After that, you are able to run your Fortnite as admin.
The fifth one is to configure your computer settings. Your PC settings might be one of the possible reasons for Fortnite not loading. If your computer is not configured properly, you will not able to make full use of your system sources and will have the Fortnite not loading problem. You can change the number of boot processors and adjust the settings in System Properties.