How did you build this? The issue is wrong version is reference. You can eliminate this error by opening the Manifest file in the OSGI bundle and remove version. Then the bundle will pick up version AEM exposes.
You need to use Sling Models. You can find the answer in this AEM HELPX COMMUNITY Article: Adobe Experience Manager Help | Creating a HTL Repeating Data Set 6.4 Component that uses Sling Models Hope this helps...
This article shows you exactly how to interate through a collection (Multifield) using HTL:Adobe Experience Manager Help | Creating a HTL Repeating Data Set 6.4 Component that uses Sling Models