We are trying to publish data from DB2 source to SQL Server target. We use SEQLOV to pick a specific rows from source based on a criteria. The query works fine from the Datamaker SQL window & from Oracle SQL Developer but it goes to hung state when we try to validate in the data painter/publish. 

Below are the Generator service logs from portal:

2019-11-19 20:14:04.017 UTC [ERROR] [https-jsse-nio-8443-exec-2] --- [U:Administrator][M:POST][P:/api/ca/v1/generators/validateExpression]                      c.c.t.g.s.DataPainterService:  Expression validation failed, org.springframework.web.client.HttpServerErrorException: 500 null

2019-11-19 20:14:04.017 UTC [ERROR] [https-jsse-nio-8443-exec-2] --- [U:Administrator][M:POST][P:/api/ca/v1/generators/validateExpression]                   c.c.t.g.c.DataPainterController:  Expression validation failedjava.lang.Exception: (500)500 

2019-11-19 20:14:04.017 UTC [ERROR] [https-jsse-nio-8443-exec-2] --- [U:Administrator][M:POST][P:/api/ca/v1/generators/validateExpression]              c.c.t.c.e.h.GlobalExceptionConvertor:  HTTP Error - INTERNAL SERVER ERROR: Exception: (500)500 

java.lang.Exception: (500)500 

at com.ca.tdm.generators.service.DataPainterService.validateExpression(DataPainterService.java:258)

at com.ca.tdm.generators.controller.DataPainterController.validateExpression(DataPainterController.java:266)

at sun.reflect.GeneratedMethodAccessor2997.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)