Android Studio 3.0 Execution failed for task: unable to merge dex

Question

android studio was getting build error while build execution with following:

Error:Execution failed for task \':app:transformDexArchiveWithExternalLi

Answer 1

This error happens when you add an external library which may not be compatible with your compileSdkVersion .

Be careful when you are adding an external library.

I spent 2 days on this problem and finally it got solved following these steps.

• Make sure all your support libraries are same as compileSdkVersion of your build.gradle(Module:app) in my case it is 26.

• In your defaultConfig category type multiDexEnabled true. This is the important part.

• Go to File | Settings | Build, Execution, Deployment | Instant Run and try to Enable/Disable Instant Run to hot swap... and click okay

• Sync Your project.

• Lastly, Go to Build | click on Rebuild Project.

• Note: Rebuild Project first cleans and then builds the project.