Error Refreshing SQL Endpoint in Microsoft Fabric – “Value cannot be null. Parameter name: key”

[Edward_Vabi]

Hi everyone,
I’m encountering an issue in Microsoft Fabric when trying to refresh my SQL endpoint. I get the following error:

Value cannot be null. Parameter name: key

My semantic model shows very old refresh dates, even though the underlying data is being refreshed daily. This is affecting my reports since the model doesn’t reflect the latest data.

Has anyone experienced this error before or know what might be causing it? Any ideas on how to troubleshoot or fix it would be appreciated.

Thanks in advance!

[v-saisrao-msft]

Hi @Edward_Vabi,
I hope this information is helpful. Please let me know if you have any further questions or if you'd like to discuss this further. If this answers your question, please Accept it as a solution and give it a 'Kudos' so others can find it easily.
Thank you.

[Edward_Vabi]

HI @nilendraFabric  - i have this turned on but for some reason the tables do not sync - plus i get this error  when i try synching 

[v-saisrao-msft]

Hi @Edward_Vabi,

We haven’t heard back from you regarding your issue. If it has been resolved, please mark the helpful response as the solution and give a ‘Kudos’ to assist others. If you still need support, let us know.

Thank you.

[v-saisrao-msft]

Hi @Edward_Vabi,

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

[v-saisrao-msft · Accepted solution]

Hi  @Edward_Vabi,

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

Thank you @nilendraFabric, for your insights.

Thank you for providing details about the "Value cannot be null. Parameter name: key" error you're encountering when refreshing your SQL endpoint in Microsoft Fabric. Since you’ve confirmed that the “Sync the default model” setting is enabled, yet the semantic model remains outdated and the error persists, this issue likely stems from a configuration. 
First verify the schema of your Lakehouse or Warehouse to ensure all tables and columns referenced in the semantic model are intact and haven’t been renamed or deleted, as schema mismatches can trigger this error. Check the semantic model’s Model View to confirm that primary keys and relationships are correctly defined and not referencing null or missing fields, as the “key” in the error often points to such issues. 

Check the Refresh History in the Fabric workspace for detailed error logs, which may pinpoint specific tables or columns causing the failure. As a last resort, consider creating a new semantic model to rule out corruption, reconnecting it to the same data source, and testing a refresh.

If this post helps, then please give us ‘Kudos’ and consider Accept it as a solution to help the other members find it more quickly.

Thank you. 

[Edward_Vabi]

thank you for this @v-saisrao-msft - i have not had time to try these yet  but let me revert ones i do, should get around to this by end of this week

[v-saisrao-msft]

Hi @Edward_Vabi,

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

[nilendraFabric]

Hello @Edward_Vabi 

The most frequent cause for the default semantic model not updating is the “Sync the default model” setting being turned off. This setting controls whether the model automatically syncs with new data in your Lakehouse or Warehouse.

https://community.fabric.microsoft.com/t5/Fabric-platform/Cannot-refresh-or-create-semantic-models/m...