Error: package android.support.annotation does not exist

[ifll]

After using anychart's android library to develop an app within android studio, and successfully running it via usb to a smartphone, when I try to "make project" to compile it, the following error appears:

"C:\~\anychart\src\main\java\com\anychart\chart\common\dataentry\DataEntry.java:3: error: package android.support.annotation does not exist
import android.support.annotation.NonNull;"

So I can run the app when debugging it with a smartphone via USB cable within android studio, but I cant make the project...

any idea why so?

[ifll]

I found the problem, it seems some of the imports were not found anymore

the following imports:

android.support.annotation.NonNull 
  -->   C:\~\anychart\src\main\java\com\anychart\chart\common\dataentry\DataEntry.java

switched to:
import androidx.annotation.NonNull;

and

android.support.annotation.Nullable   --> 
  C:\~\anychart\src\main\java\com\anychart\AnyChartView.java

switched to:
import androidx.annotation.Nullable;