topic Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table in Dataflow

Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Anonymous — Fri, 09 Jun 2023 15:09:54 GMT

I am inconsistently getting this error across refreshes when loading to a lakehouse from a Gen2 Data flow (this is loading from an original dataflow)

Sometimes the refresh completes - sometimes it does not - when it fails on seemingly different entities within the Gen 2 dataflow I receive the following error.

'null Error: Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: Expression.Error: We cannot convert the value null to type Table.'

Any help greatly appreciated

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

miguel — Fri, 09 Jun 2023 15:11:48 GMT

Hey!

Are you using a gateway by any chance? I'd recommend upgrading to the latest version of the Gateway. If that is still giving you issues, please reach out to our support team so they can do a more thorough investigation.

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Anonymous — Fri, 09 Jun 2023 15:13:43 GMT

I am using a cluster of gateways both with the latest release - whats the best way to contact the support team ?

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

miguel — Fri, 09 Jun 2023 15:27:42 GMT

You can create a support request through Microsoft Fabric Support and Status | Microsoft Fabric

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Anonymous — Tue, 13 Jun 2023 12:24:53 GMT

Hi,

Exactly same error message. Did you get any solution? Thanks

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Anonymous — Wed, 14 Jun 2023 11:21:04 GMT

I have a call with a Microsoft Engineer tomorrow morning - will update after that.

Just out of curiousity how are you trying to load data ? we see this issue with dataflows, sql server, oracle databases and sharepoint as sources.

We have a cluster of gateways and our capacity is hosted in EMEA

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Anonymous — Wed, 14 Jun 2023 15:09:02 GMT

I am using a SQL Server on-prem as source with latesest version of the gateway.

From source to dataflow, all tables work but from DF to lakehouse, random tables are failing.

This is one of the error messages I can have

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Anonymous — Wed, 14 Jun 2023 20:53:12 GMT

Sounds like exactly the same situation - once i have met with the Microsoft aupport engineer I will update this post

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

SidJay — Sun, 18 Jun 2023 07:59:01 GMT

Could you please try upgrading to the latest Gateway (version 3000.178.9 released on June 15th). That should help address at least one class of errors involving output destinations and/or queries that depend on other staged queries.

Please let us know if the issues persist after that. Thanks.

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

amolt — Tue, 27 Jun 2023 13:08:33 GMT

Hello SidJay,
I have updated the gateway and manually restarted the loading. No more errors!
I'll wait for the scheduled executions and update my post.

thanks

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Anonymous — Tue, 08 Aug 2023 08:30:53 GMT

This should now be fixed - we worked with the product team and it was addressed in a release last week

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

SidJay — Tue, 08 Aug 2023 08:37:37 GMT

Hi Bryan,

Thanks for confirming that this is now fixed. The fix requires updating to the latest Gateway (3000.182.5) released on August 2nd.

Thanks

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

Rarely — Tue, 08 Aug 2023 15:24:31 GMT

Hi there, I upgraded the gateway as suggested.

Still getting the same error!?:

Mashup Exception Error Couldn't refresh the entity because of an issue with the mashup document MashupException.Error: We cannot convert the value null to type Table. Details: GatewayObjectId: 6dbdaa7f-85eb-44e3-93b9-627e525dca7f

Any help would be appreciated.

Many thanks

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

miguel — Tue, 08 Aug 2023 15:31:05 GMT

Please reach out to our support team so they can take a closer look with the engineering team. You can use the link below to raise the support ticket:

https://support.fabric.microsoft.com/support

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

SidJay — Tue, 08 Aug 2023 17:49:39 GMT

Hi Bryan,

If you're able to share a few Request IDs and Session IDs for recent failures with this issue, we can start to look into the issue in parallel (while a support ticket is filed).

Thanks

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

mkruk — Wed, 04 Oct 2023 13:20:44 GMT

Is there any movement on this subject as I am getting the same error loading from Synapse to DF Gen 2.

Re: Gen2 Dataflow load to Lakehouse error - We cannot convert the value null to type Table

miguel — Wed, 04 Oct 2023 13:59:32 GMT

The issue from this topic was previously addressed. If you're encountering this error message, the root cause might be a new one. Could you please create a new topic / thread and add as many details as possible as to how to replicate the issue?