Refresh issue with Gen1 dataflows linked to Gen2 dataflows

[mathsab]

Hello,

I'm having a problem refreshing dataflows.

I have Gen2 dataflows hosted in one workspace (a workspace with a Fabric capacity license).
I then have Gen1 dataflows in other workspaces (workspaces with Premium Per User licenses).
These Gen1 dataflows are linked to the Gen2 dataflows, meaning they use the Gen2 dataflows as data sources via the "PowerPlatform.Dataflows" connector.

Scheduled refreshes of the Gen1 dataflows fail very often, and randomly. One day a dataflow refreshes correctly, the next day it fails. There are no problems refreshing the Gen2 dataflows, the problem lies with the Gen1 dataflows.
The error message is always "Error: Expression.Error: The key didn't match any rows in the table."
The data sources for the Gen2 dataflows are SQL databases, whose structure does not change.
The scheduled refresh times between the Gen2 and Gen1 dataflows are well spaced out to avoid any overlap.

Does anyone have any ideas on how to solve this problem?

Thank you in advance for your help.

[v-ssriganesh]

Hello @mathsab,

We hope you're doing well. Could you please confirm whether your issue has been resolved or if you're still facing challenges? Your update will be valuable to the community and may assist others with similar concerns.

Thank you.

[v-ssriganesh]

Hi @mathsab,

Thank you for posting your query in the Microsoft Fabric Community Forum, and thanks to @GilbertQ & @Poojara_D12 for sharing valuable insights.

Could you please confirm if your query has been resolved by the provided solutions? This would be helpful for other members who may encounter similar issues.

Thank you for being part of the Microsoft Fabric Community.

[GilbertQ]

Hi @mathsab 

What it sounds like to me is there are certain times when the expected data is not there in the data flow Gen 1. What I would recommend doing is to schedule the data flow at a time when you know it is refreshed successfully in the past to see if that resolved your data issue.

[Poojara_D12 · Accepted solution]

Hi @mathsab 

The issue you’re facing with Gen1 dataflows failing to refresh when linked to Gen2 dataflows—despite the Gen2 dataflows themselves refreshing successfully—is a known compatibility and reliability problem that arises from the architectural differences between Power BI Dataflows Gen1 (running on the legacy Power BI engine) and Gen2 (running on the new Fabric Dataflow engine). The error message “Expression.Error: The key didn’t match any rows in the table” typically indicates that the Gen1 dataflow is attempting to access an entity or field in the Gen2 dataflow that is momentarily unavailable, renamed, or temporarily locked during refresh or caching. Since your Gen2 dataflows refresh consistently and the SQL structure remains stable, the issue is most likely due to intermittent connectivity or synchronization failures between the Gen1 and Gen2 environments, especially given that they’re in different licensing capacities (Fabric vs. PPU). To mitigate this, you can try re-establishing the dataflow link by clearing the cached connections and reconnecting via the PowerPlatform.Dataflows connector, or exporting and recreating the Gen1 dataflows as Gen2 dataflows within the same Fabric workspace to ensure consistent refresh orchestration. Alternatively, staggering refresh schedules further apart or introducing a short buffer delay between the Gen2 and Gen1 refreshes can sometimes stabilize the dependency chain.