Cary.yu Jest uses Gson, it's not an incompatibility. However, I see you're using Gson 2.2.2, while Hibernate Search 5.6.2.Final (and Jest 2.0.4) are designed to use Gson 2.6.2. Your setup is unlikely to work correctly.

I suggest you check your dependencies and your classpath: your application should use Gson 2.6.2 and only this version (you shouldn't have both 2.2.2 and 2.6.2 in your classpath).
Please tell me if this solves your problem, so I can close this ticket.