Gradle failed to sync with 'unable to find optional library'

Question

I had to reinstall my system and today I get this error in Android Studio when I try to sync with gradle:

Warning: Unable to find optional library: org.apach         


        

Answer 1

To save time 2 solutions are best and works for me.

Solution 1 :

open your android sdk manager and reinstall API 23 (remove and install again).

Solution 2 :

Download this file which contain optional.json file extract and move optional.json to :

C:\Users\\AppData\Local\Android\sdk\platforms\android-23\optional