Shader compiler initialization error :Failed to read D3Dcompiler_47.DLL

i am getting this error from yesterday, before few days i installed unity 2020 lts and i was making my first game so after 2 days the whole screen and ui of unity got pink ,so i installed unity 2019 ,now when i open unity 2019 so it says
{{ “failed to read D3Dcompiler DLL file ,something preventing access to d3dcompiler_47.dll file, check your editor installation integrity, file access rights and antivirus configuration.”}]

plz help me what should i do ,i was enjoying making my first game and before it got complete ,i got this horrible error
my windows is windows 10 and unity 2019…Thanks in Advance:)

I was facing the same problem but resolved it i have uninstall the 2020 version and downloaded 2021 version now it is opening and working properly