SDK Build Tools version 20 < 23

Questions & Answers
1

Whenever I try to build in Android, it says: SDK Build Tools version 20 < 23.

I opened the SDK manager, and I installed everything for API level 23.
I made sure the sdk location was correct in the preferences.

I still get the problem.

I am using Unity 5.5.0f3 Personal (64 bit).

2

Updating your project to a newer unity version can be a solution to this problem, if nothing else works try updating your unity version. I updated my project from unity version 29.2.11f1 to 2019.4.4f1 and the issue went away for me.

3

problem fixed here : Update android sdk unity 2019 | Android sdk outdated - YouTube