topic Re: General exception - Logs reference column/object that's not in data source in Qlik Compose

General exception - Logs reference column/object that's not in data source

aspence — Fri, 14 Mar 2025 20:49:07 GMT

Hi!

Testing out compose and have gotten an error that I after a lot of troubleshooting still don't understand.

In the web gui I get this:

And when searching the logs I can find the corresponding error here:

82 2021-12-09 13:49:12 [Host ] [WARN ] Object reference not set to an instance of an object. System.NullReferenceException: Object reference not set to an instance of an object. at Attunity.Compose.BwAutomationManager.ETLUtil.ExpressionRolesDictionary(List`1 columnExpList, List`1 entityStagingInfo) at Attunity.Compose.BwAutomationManager.ETLsImp.StagingETLsImp.A(Int32 , List`1 , Boolean ) at Attunity.Compose.BwAutomationManager.ETLsImp.StagingETLsImp.A(Int32 ) at Attunity.Compose.BwAutomationManager.ETLsImp.StagingETLsImp.A(EntEtlInfo , List`1 , List`1 , List`1 ) at Attunity.Compose.BwAutomationManager.ETLsImp.StagingETLsImp.HandleStagingAndErrorMarts(List`1 createdScriptsNames) at Attunity.Compose.BwAutomationManager.ETL.A(Int32 , List`1 ) at Attunity.Compose.BwAutomationManager.ETL.GenerateETL(Int32 etlID, String userName, List`1 createdScriptsNames) at Attunity.Compose.BwAutomationManager.DataWarehouseRestImp.GenerateDWHETLs(GenerateDWHETLsParams param, GenerateDWHETLsReq req)

The thing is, userName (which I assume is the culprit) is not a field in our data source. Nor is it something I've mapped to.

The error is consistent and repeated in the logs, they all look the same.

Is userName an internal object that it can't find? Any ideas?

Re: General exception - Logs reference column/object that's not in data source

aj96 — Tue, 14 Dec 2021 18:46:48 GMT

Hi @aspence

On the mapping window Click on the change view and see if any the column is having an empty Lookup or Expression. Like below

If you do then create an expression and click on the cross button to delete it

Or map something to that column. That should fix the issue.

Re: General exception - Logs reference column/object that's not in data source

robertcur — Fri, 18 Nov 2022 08:17:15 GMT

Aspence,

To be honest, the error messaging on Compose is not very good. I've struggled a lot with errors like this and you will get more and more of these type of stupid errors. But, what I normally do is to by way of deduction sort out the "Object reference not set to an instance of an object". I assume this is when you generate the Tasks. Generate one mapping at a time. Then, once you know which one it is, take off field mappings until you get to the culprit.

@aj96 is 100% correct, that this can be a missed lookup or expression...but one really does not always know.