Eclipse+ADT

I encountered an error while running the code today

[2022-01-10 21:57:18 – Dex Loader] Failed to load D:\Android SDK\android-sdk-windows\build-tools\29.0.3\lib\dx. jar
[2022-01-10 21:57:18 – BrewClock] Unknown error: Unable to build: the file dx. jar was not loaded from the SDK folder!

Cause: Eclipse automatically uses the highest version of the SDK, and ADT is lower than the SDK version

Solution:

Open SDK manager.exe download the minimum version of buildtools 20 21

Open project.properties, fill in the last line with SDK.buildtools=21.0.0

21.0.0 is the version number of buildtools you downloaded

You can find it in D:\Android SDK\ Android-SDK-windows\build-tools file

Save and run again