error appcompat_v7 ko - XoilacTV

One of the common errors after installing Android Studio is the appcompat-v7 error. This error occurs due to the banning of Iran IPs and as a result of not receiving the file through Android Studio for users who launch their project from Iran.

When I use com.android.support:appcompat-v7:28.+ in my project's build.gradle (module) it works without any error. But when I just use com.android.support:appcompat-v7:28, just without .+, it gives me an error:

Android AppCompat Library V7. The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later. This artifact was moved to:

Try this: 1) tools -> android -> sdk manager -> Launch Standalone SDK Manager. 2) find "extras -> Android support repository" and check it (uncheck other for faster installing) 3) click install. Tip: Also use File -> Invalidate Caches / Restart if android studio does something strange. It may help in some cases.