Unity should remember these settings after the first time
This path also can be specified in Unity-Preferences…-External Tools-AndroidSdk path
Or just try to save the project afterf path selection.
@intrikit Hope I am not too late, I just suffered this issue there, according to can not select android root folder - Unity Answers - Android SDK uses two paths, I originally had C:\Program Files (x86)\Android\android-sdk
which was causing the issue, so I changed the “Android SDK” path via [Unity] “Edit > Preferences > External Tools” to C:/Users/User/AppData/Local/Android/Sdk
, which has allowed me to build my game successfully.