I can't open any project. It loads to 45% and then stops. I wait ages and it doesn't open! How can I fix this?

open the task manager in windows and you will see the compilation of shaders in the process UnrealEngine. After the compilation is finished, the download will continue.

I can’t open any project. It loads to 45% and then stops. I wait ages and it doesn’t open! How can I fix this?