Refreshing semantic model does not work

[Nikos83]

Hi Community,

Since yesterday, we’re encountering major issues refreshing our semantic models in Microsoft Fabric.
We consistently receive the following error:
Failed to save modifications to the server. Error returned: 'We cannot access the source Delta table gta_dim_aanmaning'
referenced by table 'gta_dim_aanmaning'.
Either the source Delta table does not exist, or you don't have access permissions.
Consider removing the table from the model. Please refer to https://go.microsoft.com/fwlink/?linkid=2248855 for more information

However:
- The Delta table does exist
- Permissions are correctly configured
- The table can be queried successfully via the SQL Analytics Endpoint

We’ve already tried the following:
- Deleted and recreated the table in the Lakehouse, refreshed metadata in both the Lakehouse and the SQL Analytics endpoint
- Created a new Lakehouse with a new table, and built a brand-new semantic model — the same error still occurs
- We suspect this may be an internal Fabric issue, possibly related to metadata synchronization.

We are using Microsoft Fabric in Europe West.
- Is anyone else experiencing similar issues in this region?
- What else can we try to resolve this?

At the moment, all our dashboards are broken (all visuals show error crosses), and we are unable to build or update any semantic models.

Any help is greatly appreciated — this is business-critical for us.

Thanks in advance!

[v-venuppu]

Hi @Nikos83 ,

Thank you for the Update..!!

Please let us know if you need any further assistance, we are happy to help.

[Nikos83]

The issues with our semantic models have been resolved. They were related to a problem that recently occurred in the French region. It turned out to be a synchronization issue in the metadata coming from the lakehouse.

All our semantic models can now be updated again, and the dashboards are displaying correctly.

[v-venuppu]

Hi @Nikos83 ,

Thank you for reaching out to Microsoft Fabric Community.

Thank you @KevinChant @rohit1991 for the prompt response.

I wanted to check if you had the opportunity to review the information provided by @rohit1991 and resolve the issue..?Please let us know if you need any further assistance.We are happy to help.

Thank you.

[KevinChant]

Are you experiencing the issue when you attempt to perform a refresh? If so, have you opened up your semantic model and checked that it is absolutely pointing to the right workspace and Lakehouse?

[Nikos83]

Yes, problem also occurs when i am refreshing the semantic model. And yes, the semantic model is pointing to the right workspace and lakehouse

[rohit1991]

Hi @Nikos83 

Root Cause: Even though the Delta table exists and is accessible via SQL Endpoint, Microsoft Fabric sometimes fails to sync the table's metadata properly with the semantic model especially after schema changes or table recreation.

 Steps :

1. Go to the Lakehouse where your Delta table is stored.
2. In the “Tables” section, delete the existing table reference (not the actual Delta file, just the reference).
3. Click “New Table” >> “From Files”, and re-add the same Delta table again.
   >> This forces a fresh metadata sync with the Lakehouse.
4. Then, go to your Semantic Model, remove the old table (if still linked), and add the newly re-linked table from the Lakehouse again.
5. Now try refreshing the semantic model

[Nikos83]

Thanks for your quick repley.

I’ve already created an entirely new Lakehouse with a brand-new table in it, and I’m experiencing exactly the same issue there. I think microsoft is having some problems related to their meta data synchronisation 

[rohit1991]

Hi @Nikos83 

Thanks for the update and you're absolutely right, Microsoft Fabric has had ongoing intermittent issues with metadata sync, especially when:

1. Tables are recreated (even with new names),
2. Or when schema changes are involved,
3. And even in brand-new Lakehouses as you mentioned.

Try this forced metadata rebuild trick:

1. Delete the semantic model completely from the workspace (not just refresh).
2. In the Lakehouse:

          a.  Go to the Delta table folder >> Temporarily rename the *_delta_log folder (e.g., to                                               _delta_log_backup)

          b. Wait a few seconds, then rename it back to _delta_log.

              This forces Fabric to re-evaluate the table metadata on next connection.

3. Then recreate the semantic model from scratch using the re-added table.

 Optional Check:

Open the SQL Endpoint and run:

sqlCopyEditSELECT * FROM INFORMATION_SCHEMA.TABLES