Same issue with Version: 4.25.1-13594126+++UE4+Release-4.25 on my computer as well. Stuck at 39% when RayTracing is enabled for a project. The Shader Compile Working runs forever on 100% CPU. I have a GTX 1050 Ti GPU and GeForce drivers 446.14 installed.
Setting the r.SkinCache.CompileShaders=False in the DefaultEngine.ini made the editor start fast.