My App was working fine, then i add com.splunk:mint-android-sdk, which required upper version of gradle, so i upgrade the gradle to from 2.1 to 3.3. after that i am facing i
Please follow these steps :
Open Your project.
Go to the Left side of the Gradle button.
Click button above image show .
if this type of view you are not in offline mode.
Go to Build and rebucild the project.
The above worked for me.
I've got this error, and the problem was the antivirus Avast blocking android studio from download the files.
so I've disabled it temporary and also runned Android studio as an admin. this solved the problem.
I resolve my problem removing proxy configuration in file gradle.properties