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.
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.
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
Maybe in most case, but not fo me. Anyway thanks for answer, i’m appreciate it If you interested check the answer