Problems with SDK and Google Admob plugin

I’m trying to add admob in my project but the build apk keeps crashing in my android device.
I’ve been trying to fix this issue for days, so any help would be appreciated.137255-sdk-and-jdk.png
And i keep getting this error “Failed getting available Android API levels. Make sure your android sdk tools version is 25 or higher and you have internet connection.
System.Threading.ThreadHelper:ThreadStart()”

What Android version are you developing for?
Have you downloaded the latest SDKs from Android Studio?