Android Studio generating an error saying “is defined multiple times”

Just delete the “build” folder of the “app” module. Afterward, please go to the Build drop-down menu in the menu bar. You can see the Rebuild Project under the Clean Project. If you can’t find Rebuild Project, you can use Clean Project instead. More solutions for this problem can be found here: https://stackoverflow.com/questions/34803518/split-lib-main-was-defined-multiple-times/45508685