How to investigate issue "An unexpected error has occured. Please retry" on HCP

We deploy same Java code to Factory and PROD landscape. It runs well in Factory landscape. But in PROD system, it will return “Sorry!An unexpected error has occured. Please retry.” when we access the odata service. How to investigate such kind of issue ?

I try to use remote debug in Eclipse, but when call one function, it will jump to another thread and stop at class org.apache.catalina.core.ApplicationFilterChain.

We use Olingo version 2.0.6-sap-04 to expose OData service.