Error 21503 using REST connector for a copy activity -

[pmscorca]

Hi,

in order to read Dynamics 365 Business Central data by the REST connector, in Manage Connections I've created a Web connection specifying https://api.businesscentral.dynamics.com/v2.0/...  (with the URL of the BC table) as a URL, OAuth 2.0 as an Authentication method and Organizational as a Privacy level.

Then, in the copy activity I've selected the Web connection created, the REST option as a Connection type and the same above URL as a Relative URL, receiveing the error 21503

According to official documentation, the OAuth2 is supported

Well, any suggests to me in order to solve a such issue, please?

Many thanks

[v-agajavelly]

Hi @pmscorca ,

I hope the response provided helped in resolving the issue. If you still have any questions, please let us know we are happy to address.

Thanks,
Akhil.

[v-agajavelly]

Hi @pmscorca ,

Just circling back, did you get a chance to test with either the Organizational account or Service Principal option? If the 21503 error is still persisting, feel free to share any new details so the community can help troubleshoot further.

Thanks,
Akhil.

[v-agajavelly]

Hi @pmscorca ,

Were you able to recreate the connection using either an Organizational account or a Service principal, and did that resolve the 21503 error for you?

Regards,
Akhil.

[v-agajavelly]

Hi @pmscorca,

The error comes because the REST connector does not support generic OAuth2.
Instead, when connecting to Business Central you need to use either:

• Organizational account (your Azure AD login), or
• Service principal (client ID + secret).

So just recreate the connection and choose Organizational account or Service principal instead of OAuth2 that will resolve error 21503.

Regards,
Akhil.

[pmscorca]

Hi, in Manage Connections respect to the Web connection type I cannot select the Organizational account as an authentication method.

Thanks

[v-agajavelly · Accepted solution]

Hi @pmscorca,

Since Organizational account is not available in the dropdown for Web connection, Need to switch from using a Web connection to a REST connector configured with supported authentication types. 
By follwoing bellow steps yo can try to achive this.

Option 1: Use Service Principal

This is the most reliable workaround. Go to Azure Portal and register an app.

Generate - Client ID - Client Secret - Tenant ID

Assign necessary API permissions to the app for Business Central.
In Fabric, create a new REST connection using.

Authentication type: Service Principal - Provide the above credentials and use this connection in your copy activity.

This avoids the OAuth2 limitation and works seamlessly with Business Central’s API.

Option 2: Use Organizational Account via Dataflow Gen2

If it insists on using Organizational account, You needs to use Dataflow Gen2 instead of a copy activity and in Dataflow Gen2, the Organizational account option is available and supported for Business Central by Authenticate using Azure AD credentials and pull the data.

If still wants to use Power BI Desktop to test the connection.

• Connect to Business Central via OData connector.
• Copy the M code from Power Query.
• Paste it into a blank query in Dataflow Gen2 in Fabric
  
  

Thanks,
Akhil.