Hi community 
This is my problem. I had Unreal Engine 4.21.2 and project called “laser” on my previous hard drive and everything was ok with shaders compiling, then i bought a new one and download Unreal Engine 4.21.2 on the new one after then when i open project on the new hard drive the shaders start to compile endlessly.
After couples hour of searching the solution with question “Why shaders compiling endlessly”, a asked another question “which process compiling shaders ue4” to Google and face with the solution How to fix UE4 4.19 not compiling shaders? (Getting stuck at 45%) - Getting Started - Unreal Engine Forums
the problem was with third-party development tool called “IncrediBuild” this is a tool included in one of Visual Studio’s coding packages who’s background service interfered with proper operation of Unreal Engine. After uninstalling it i restarted the project and verything compile fine. I don’t how he figured it out maybe he is genius. The inference is try to change your searching question
Hi
When you do a re-install like that, UE will need to progressively compile most of the shaders, just like when it’s a new package… It will stop eventually.
Maybe in most case, but not fo me. Anyway thanks for answer, i’m appreciate it If you interested check the answer