I am using android studio 3.1.4.
Error:Could not find intellij-core.jar (com.android.tools.external.com-intellij:intellij-core:26.0.1). Searched in the following loc
In addition to devsnd and Mr-IDE's answers, Here are the suggestions:
Place 'google()' in the first order in both buildscript repositories and allprojects repositories of Project-level Gradle build file.
Check the consistency in the Android Gradle Plugin version and Gradle version. Generally, they are automatically updated with Android Studio, but you might have an older project. Plugin 3.1 should use Gradle version 4.4 and above, Plugin 3.2 should use Gradle version 4.6 and above.
Install that particular buildToolsVersion that plugin uses.
Check out this link for more details:
https://developer.android.com/studio/releases/gradle-plugin#updating-gradle
Hope this helps.