What causes Fabric Copy Activity Error 20153?

The client ID was copy-pasted with an accidental colon character included, such as from a 'ClientID: ' label format. The authorization server uses a non-standard client ID format that includes a colon, which Fabric does not support. A username:password or similar compound credential string was mistakenly entered in the client ID field. Manual entry error when configuring the linked service in Fabric Data Factory

How do I fix Fabric Copy Activity Error 20153?

Step 1: Open the linked service configuration in Fabric Data Factory and locate the client ID field for the OAuth2ClientCredential authentication section.. Step 2: Inspect the current client ID value carefully for any colon (':') characters and remove them.. Step 3: Cross-reference the correct client ID value from your authorization server's application registration (e.g., the App Registration in Microsoft Entra ID) to ensure accuracy.. Step 4: Save the updated linked service and run a test connection to confirm the authentication now succeeds.. Step 5: If using a parameterized or Key Vault-referenced client ID, verify that the secret or parameter value stored externally also does not contain a colon.

Medium severityconfigurationMicrosoft Fabric →

Power BI Refresh Error:
Fabric Copy Activity Error 20153

What does this error mean?

The OAuth2 client ID configured in the linked service contains a colon character (':'), which is an invalid character for OAuth2ClientCredential authentication in Fabric. The Copy Activity will fail until the client ID is corrected.

Common causes

1The client ID was copy-pasted with an accidental colon character included, such as from a 'ClientID: <value>' label format
2The authorization server uses a non-standard client ID format that includes a colon, which Fabric does not support
3A username:password or similar compound credential string was mistakenly entered in the client ID field
4Manual entry error when configuring the linked service in Fabric Data Factory

How to fix it

1Step 1: Open the linked service configuration in Fabric Data Factory and locate the client ID field for the OAuth2ClientCredential authentication section.
2Step 2: Inspect the current client ID value carefully for any colon (':') characters and remove them.
3Step 3: Cross-reference the correct client ID value from your authorization server's application registration (e.g., the App Registration in Microsoft Entra ID) to ensure accuracy.
4Step 4: Save the updated linked service and run a test connection to confirm the authentication now succeeds.
5Step 5: If using a parameterized or Key Vault-referenced client ID, verify that the secret or parameter value stored externally also does not contain a colon.

Frequently asked questions

Why is a colon specifically disallowed in the client ID?

In OAuth2 client credential flows, the client ID and client secret are often combined using a colon as a delimiter (e.g., in HTTP Basic authentication encoding as 'clientId:clientSecret'). Allowing a colon inside the client ID itself would break this encoding scheme, making it impossible to correctly parse the credentials.

How do I find the correct client ID for my application?

For Microsoft Entra ID (Azure AD), navigate to the Azure Portal → Microsoft Entra ID → App Registrations → select your application → copy the 'Application (client) ID' GUID. This value will not contain a colon and is in standard UUID format.