Rem I had this Problem with the Unreal Engine just run this in cmd as Admin:
mklink C:\Users\%USERNAME%\AppData\Local\Android\Sdk\build-tools\{Android Build Tools Version}\dx.bat C:\Users\%USERNAME%\AppData\Local\Android\Sdk\build-tools\{Android Build Tools Version}\d8.bat
mklink C:\Users\%USERNAME%\AppData\Local\Android\Sdk\build-tools\{Andriud Build Tools Version}\lib\dx.jar C:\Users\%USERNAME%\AppData\Local\Android\Sdk\build-tools\{Android Build Tools Version}\lib\d8.jar


Rem Source: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj80ojZsML0AhWZhv0HHfE0CmQQFnoECAQQAQ&url=https%3A%2F%2Fourcodeworld.com%2Farticles%2Fread%2F1591%2Fhow-to-solve-android-studio-error-installed-build-tools-revision-3100-is-corrupted-remove-and-install-again-using-the-sdk-manager&usg=AOvVaw2wklch_RG9Ag3zjcW_GKjl