I just downloaded Visual Studio 2019 and Xamarin because I want to start developing mobile applications with C#, however, several of the Android SDK components were out of date or not installed. I have been able to install and update all of them (I think) except for the Android SDK Build Tools which throws an error every time I try to start downloading the update. I originally had version 25.0.3 downloaded and it was prompting me to download version 28.0.3. After I uninstalled version 25.0.3 it stopped asking me to update, but told me that I had a missing component, and trying to install version 28.0.3 was still throwing an error. I reinstalled version 25.0.3 and it started telling me to update again which I cannot do. How do I install the Android SDK Build Tools v28.0.3?
This problem should not be present in the latest version of Visual Studio.
You can try this: Go to Tools -> Options -> Xamarin -> Android Settings and check the "AutoInstall Android SDKs" checkbox. Then double-click on the error and it should resume installation of the missing SDK.
I circumvented the problem by downloading the Build Tools here: https://androidsdkmanager.azurewebsites.net/Buildtools I then simply unzipped them to the build-tools folder at "C:\Program Files (x86)\Android\android-sdk\build-tools". Everything seems to be working fine now.