Android Question [SOLVED]Maven artifact not found: androidx.documentfile/documentfile

[Almog]

Hello!

I tried to run an app uses NB6 and User activity recognition, but the compiler showed this Error:

Organizing libraries.    Error
Maven artifact not found: androidx.documentfile/documentfile

I switched to AndroidX SDK, Installed all recommended items, and installing JDK 8, but the problem still exists.

Does anybody know what the problem is and how can I fix it?

Thanks in advance

 

[Almog]

Solved. I redownloaded the android folder with the android.jar file and downloaded all the recommended items.