Using HAPI/FHIR

I have previously done a simple POC with succes.
I’m getting an error trying to implement a Java UPOC, basically trying to make a JSON -> FHIR XML conversion.
I see the error from the Testing Tool, so I am guessing that I would get the same error from within Cloverleaf.
Is it possible to get more information on exactly causes the Exception ?

The error is :
[0:TEST] Tcl error: msgId = message0 proc = ‘cljTPS’ args = ‘{CLASS Json2FhirXML} {ARG1 {This is argument 1}} {ARG2 {This is argument 2}} {FILESET {{OBFILE /tmp/xxx} {OBAPPEND 0} {FILENAME {{DIR /tmp} {FILE yyy}}}}}’
result = ‘com.quovadx.cloverleaf.upoc.CloverleafException: Could not instantiate user-defined class Json2FhirXML InvocationTargetException: null’ errorInfo: ‘ com.quovadx.cloverleaf.upoc.CloverleafException: Could not instantiate user-defined class Json2FhirXML InvocationTargetException: null at com.quovadx.cloverleaf.upoc.CloverEnv.makeUpocInstance(CloverEnv.java:1345) invoked from within “makeUpocInstance $className TPS $__userArgsCfgs” (procedure “cljTPS” line 35) invoked from within “cljTPS {MSGID message0} {CONTEXT sms_ib_data} {ARGS {{CLASS Json2FhirXML} {ARG1 {This is argument 1}} {ARG2 {This is argument 2}} {FILESET {{OBFILE /t…”‘

This is on Cloverleaf version 2022.09.03
I have added the – I hope – relevant (5.5.0) jar files and the class file in $HCISITEDIR/java_uccs
Using the latest 8.0.0, gave me an error stating that something was compiled with at later version of Java.
I have attached the Java code.

Thanks in advance.

Yours sincerely

Ib Højme