Event Schema Inside Eventstream Never Matching

[Kelderic]

I am exploring the new Event Schemas as a way to pre-define my schemas and replace the multiple-schema inferencing. I have created a Event Schema Set, with three Event Schemas, all very simple with five or less columns each.

In the screenshot above, one schema shows two fields."TermsCode" and "Description", both string.

I've created a new Event Stream, and associated it with the event schemas:

I then pushed in data, which in the preview, shows the correct matching headers. But the data is only seen as "Unknown schema":

Has anyone gotten event schemas to work?

Edit: I am using the new Event Schemas system, rather than Multiple Schema Inferencing. These are different and exclusionary. I have event streams working with inferred multi-schema and I'm trying to switch to defined event schemas.

[v-sshirivolu]

Hi @Kelderic ,
Thanks for reaching out to Community Forum.

The issue happens because Fabric Eventstream strictly validates schemas at runtime. Even if preview looks correct, any mismatch in field names, structure, or data types causes events to be marked as Unknown schema. Also, schema support must be enabled during Eventstream creation, and for multiple schemas, explicit matching rules are required.

Fix by recreating the Eventstream with schema enabled, ensuring the payload exactly matches the schema, and configuring schema mapping if multiple schemas are used. Check diagnostics logs to identify mismatches.

Refer these docs:

https://learn.microsoft.com/en-us/fabric/real-time-intelligence/schema-sets/use-event-schemas
https://learn.microsoft.com/en-us/fabric/real-time-intelligence/schema-sets/schema-registry-limitati...
https://learn.microsoft.com/en-us/fabric/real-time-intelligence/event-streams/add-source-azure-event...
https://learn.microsoft.com/en-us/fabric/real-time-intelligence/event-streams/process-events-with-mu...

Thank you.

[Kelderic]

Hi there, thanks for the response.

The issue happens because Fabric Eventstream strictly validates schemas at runtime. Even if preview looks correct, any mismatch in field names, structure, or data types causes events to be marked as Unknown schema.

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This is what I suspect as well, but as the screenshots show, the data appears to match the pre-defined schema perfectly.

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Check diagnostics logs to identify mismatches.

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How do I see these?