I am not sure what this error means.
Execution failed for task \':excelSior:packageAllDebugClassesForMultiDex\'. > java.util.zip.ZipException: duplicate
This is because you have added a library and given its dependency on a module more than once.
In my case, I had added a library as a module and as a gradle dependency both.
Removing one source of adding library (I removed gradle dependency) solved my problem.