Failed to resolve: com.android.support:appcompat-v7:28.0

28.0.0 is the final version of support libraries. Android has migrated to AndroidX. To use the latest android libraries, Migrating to AndroidX

Edit: Versions 28.0.0-rc02 and 28.0.0 are now available.

I don’t see any 28.0 version on Google Maven. Only 28.0.0-alpha1 and 28.0.0-alpha3. Just change it to either of those or how it was previously, i.e., with .+ which just means any version under 28 major release.

For an alpha appcompat release 28.+ makes more sense.