After upgrading my Android Studio to the latest version, I encountered problems with the Gradle version of my old Android project. The error message is saying something like the following "Gradle version 2.10 is required. Current version is 2.8. Fix Gradle wrapper and re-import project Gradle settings." A screenshot of the error is shown below.
Sometimes, clicking on the Fix hyperlink will resolve the problem; but sometimes it does not. If it does not, then it is possible to fix the problem by editing the gradle-wrapper.properties file of your project in the editor as shown below.
Simply change the version number in the distributionUrl to the new required version e.g. https\://services.gralde.org/distributions/gradle-2.10-all.zip.