XML のエラー

SDK processing. This version only understands SDK XML versions up to 3 but an SDK XML file of version 4 was encountered. This can happen if you use versions of Android Studio and the command-line tools that were released at different times.

参考

https://stackoverflow.com/questions/70368175/why-am-i-getting-this-warning-and-how-to-resolve-it-this-version-only-understan

click "Repair IDE" in the Android Studio.