We cannot convert the value null to type Record.

[rauldantas]

My reports were updating normally until yesterday. Now most of them are giving the following error: Expression.Error: We cannot convert the value null to type Record.. Microsoft.Data.Mashup.ErrorCode = 10277. . The exception was raised by the IDbCommand interface.

The problem is that in Power BI Desktop I can update without any problem, but in Power BI Service / Online it ends with this error.

At the end of the error it shows a table. But each report shows a different table, so I don't think that's the problem.

[rauldantas · Accepted solution]

I managed to solve the problem.

The problem is in the connector with my datalake, which is Dremio.

What used to be
= Dremio.DatabasesV370(Dremio_Fonte, "Disabled", null, null, null)

It changed to:
= Dremio.DatabasesV370(Dremio_Fonte, "Disabled", null, null, null, [])

I made the change in the reports and it is updating normally now.

[cultcargo]

Thank you for sharing the fix!
We, in Dremio, have updated our doc page with this mitigation steps.
For Cloud connector
DremioCloud.DatabasesByServerV370(servername, projectId, engine, routingTag, routingQueue, encryption, [])

And for Software connector
Dremio.DatabasesV370(servername, encryption, engine, routingTag, routingQueue, [])

I would like to highlight, that the number of arguments for Cloud connector function (DatabasesByServerV370) is +1 compare to the Software connector (Dremio.DatabasesV370). Only the very last null argument should be changed to []. So, it is 7th argument in case of DremioCloud.DatabasesByServerV370 and 6th in case of Dremio.DatabasesV370.

The fix is also submitted to Microsoft for the next release of the connectors in upcoming weeks.

[v-pgoloju]

Hi @rauldantas,

Thank you for reaching out to the Microsoft Fabric Forum Community.

The “Expression.Error: We cannot convert the value null to type Record” arises when a step in Power Query expects a record but receives null, something that the Power BI Service (full, server‑side refresh with stricter connector/privacy rules) catches even if Desktop doesn’t. Pinpoint the exact failing Applied Step by stepping through the query, then add a defensive wrapper such as try <step> otherwise null or if Value.Is(x, type record) then x else null. before any record expansion or field access. Next, verify in the Service that every parameter, credential, and privacy level is correctly set (all sources usually Organizational). Common root causes include blank rows returned overnight, nested JSON fields that are sometimes null, joins whose right‐hand query failed in the Service, and prod/dev parameter mismatches. After wrapping the risky step, refresh in Desktop (clearing permissions first), republish, and trigger a Service refresh errors should disappear.

If you found this response helpful, please consider marking it as the accepted solution and giving it a thumbs-up to help others in the community.

Thank you & best regards,
Prasanna Kumar