Unable to connect SAP datasphere in Power BI desktop

[Ynr0225]

Hi All,

I have downloaded the SAP_DWC_01.mez custom connector from Github in order to connect SAP data sphere in Power BI desktop. Few days back we are able to connect it in Power BI desktop with out any issues. Now suddenly dont know what happend we are unable to connect it. Below is the error message we are receiving

Could any one suggest what happends, it suddenly not connecting in Power BI Desktop

[Jaywant-Thorat]

Hi @Ynr0225 

Got it, this error is very specific and usually not random.

Error: Details: [DataFormat.Error] We found an unexpected character in the JSON input.

This means, Power BI received invalid JSON from SAP Datasphere OData endpoint. It is not a Power BI issue.
It is either:

• Connector issue
• SAP response format changed
• Authentication expired
• Parameter formatting issue

Most Common Reasons:
1) Power BI Desktop Updated (Very Common)

If Power BI auto-updated recently:

• Custom connector (.mez) may no longer be compatible
• SAP_DWC_01.mez may need update

Check:
File >> Help >> About >> Compare version with last working version.

If updated recently, this is likely the cause.

2) SAP Datasphere Changed OData Response

If:

• View was modified
• Parameter structure changed
• KEY_DATE format changed
• OData version switched

It may now return:

• HTML error
• Empty response
• Auth redirect page

Which Power BI tries to read as JSON >> fails.

3) Input Parameter Formatting Issue

You entered: KEY_DATE=2025-08-31

Some SAP endpoints require: KEY_DATE='2025-08-31'  OR  KEY_DATE=datetime'2025-08-31T00:00:00'

Even small format change can break JSON parsing.

4) Expired Authentication / Token

Clear credentials:

1. File >> Options & Settings
2. Data Source Settings
3. Clear permissions for SAP Datasphere
4. Reconnect

Very often fixes this.

5) SAP Tenant Patch / Update

If it worked few days ago and suddenly stopped:

• SAP backend patch likely happened
• OData service changed format

Test the OData URL directly in browser or Postman.
If it shows:

• HTML
• Error message
• XML instead of JSON

Then that’s the issue.

What To Do (Step-by-Step)
Step 1: Clear Data Source permissions.

Step 2: Re-download latest SAP_DWC_01.mez from GitHub.

Step 3: Test OData URL manually in browser.

Step 4: Check if Power BI updated recently.

If it worked few days ago and suddenly stopped:

• 70% chance = SAP backend update
• 20% chance = Power BI Desktop update
• 10% chance = Authentication expired

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[Ynr0225]

Hello @Jaywant-Thorat , Thanks for helping on this.
Here i want to mention one thing, in Power BI desktop I'm able to connect to other analytical models without issue. So i think this is not a authenticate issue, Power BI upgrade issue.

[v-kpoloju-msft]

Hi @Ynr0225, 
Thank you for the clarification.

Since you can connect to other analytical models successfully, we can safely rule out authentication issues, Power BI Desktop upgrade concerns, or a general custom connector problem. This indicates the issue is isolated specifically to the analytical model S4AM_FIAR_RPT0001_GC_99_YDM or its OData exposure. The error [DataFormat.Error] We found an unexpected character in the JSON input typically occurs when Power BI expects a JSON response from the OData endpoint but instead receives a different response format (such as an HTML error page, redirect message, or malformed payload). This usually happens when there has been a recent change in the analytical model structure, parameter configuration, or OData service behaviour.

As a next step, I recommend validating whether any recent changes were made to the model (especially to the KEY_DATE parameter type or format) and confirming the exact parameter format expected by the OData service. You may also test the OData service URL directly in a browser or Postman to verify whether it returns valid JSON. If the response shows an HTML or error message instead of JSON, this will confirm a service-level issue rather than a Power BI issue.

Additionally, republishing the analytical model and ensuring OData access is still enabled can help resolve cases where the endpoint metadata may have become inconsistent.

Hope that clarifies. Let us know if you have any doubts regarding this, and we will be happy to assist further.
Thanks again for using the Microsoft Fabric Community Forum.

[Ynr0225]

Hello @v-kpoloju-msft ,

As you suggested i opened the OData URL directly from browser and i am getting below output.

Could you please let us know by seeing the screenshot ouput is it Json format?

[v-kpoloju-msft]

Hi @Ynr0225,
Thank you for sharing the screenshot.

Yes, the response shown in your browser is in valid JSON format, which confirms that the SAP Datasphere OData service is working correctly and returning proper data. This also means the issue is not with the service availability itself, but rather with how Power BI Desktop or the custom connector is processing the request for that specific analytical model. Since the endpoint is returning valid JSON, I recommend verifying the KEY_DATE parameter format, as some analytical models require it to be passed with quotes (for example: '2025-08-31') or in datetime format.

You can also try reconnecting after clearing the data source permissions and ensuring you are using the latest version of the SAP Datasphere custom connector. If the issue persists only for this model, it would be best to confirm from the SAP Datasphere side whether there were any recent changes to the analytical model or its parameter configuration, as this can affect how the connector reads the response.

Thanks again for using the Microsoft Fabric Community Forum.

[Ynr0225]

Hi @v-kpoloju-msft ,

Thanks for assisting us with this issue.

As mentioned earlier, we attempted to connect to the analytical view in Power BI Desktop after clearing all existing permissions in Power BI, but the problem still persists. Last year, we were able to connect without any issues, and at that time, we passed the KEY_DATE parameter as 2025-08-31 (without single quotes), which worked successfully.

Currently, I am not seeing any newer version of the SAP Datasphere custom connector available. If there is a link to download the latest version, could you please share it with me?

Your help is appreciated.

[v-kpoloju-msft]

Hi @Ynr0225, 
Thank you for the clarification.

Since the same analytical model worked earlier with KEY_DATE=2025-08-31 and the OData URL is currently returning valid JSON in the browser, this confirms the service is reachable and functional. This suggests the issue is likely due to a change in the analytical model metadata, parameter definition, or OData exposure in SAP Datasphere, which can affect how the custom connector interprets the response. I recommend opening the analytical model in SAP Datasphere, verifying the KEY_DATE parameter data type and configuration, and then re-saving or re-deploying the model to refresh the OData metadata.

Regarding the custom connector, the SAP_DWC_01.mez file is not maintained by Microsoft, so any updates would need to come from the original GitHub repository or SAP provider. As an additional check, please try connecting using Power BI Desktop’s built-in OData Feed connector with the same service URL. If the issue occurs only with this specific analytical model and other models work correctly, it confirms the root cause is at the SAP Datasphere model or its OData configuration, and your SAP administrator may need to review or re-publish the model.

Thank you again for using the Microsoft Fabric Community Forum.

[v-kpoloju-msft]

Hi @Ynr0225, 

Just checking in to see if the issue has been resolved on your end. If the earlier suggestions helped, that’s great to hear! And if you’re still facing challenges, feel free to share more details happy to assist further.

Thank you.

[Ynr0225]

Hi @v-kpoloju-msft ,

Checking with SAP admin team to review the analytical model in SAP data sphere

[v-kpoloju-msft]

Hi @Ynr0225, 

Thank you for the update. That’s the correct next step, as the SAP Datasphere admin can verify whether there were any recent changes to the analytical model, KEY_DATE parameter, or OData exposure settings, which may be affecting the connection from Power BI.

Once the SAP team reviews it, please ask them to re-save or re-deploy the analytical model and ensure OData access is enabled, then try reconnecting from Power BI Desktop. This helps refresh the OData metadata and often resolves connection issues. If the problem continues, please share the outcome and we will assist you further.

Thank you again for using the Microsoft Fabric Community Forum.

[v-kpoloju-msft]

Hi @Ynr0225, 

Just checking in to see if the issue has been resolved on your end. If the earlier suggestions helped, that’s great to hear! And if you’re still facing challenges, feel free to share more details happy to assist further.

Thank you.

[Ynr0225]

Hello @v-kpoloju-msft ,

The SAP Datasphere team has redeployed the Analytical model on 25th of February. Even after redeploying still we are getting same error message. So we’re not sure what might be causing the problem now

[v-kpoloju-msft]

Hi @Ynr0225, 
Thank you for the update.

Since the analytical model has already been redeployed and the OData URL returns valid JSON in the browser, the service itself appears to be working. As a next step, please try connecting using Power BI Desktop’s built-in OData Feed connector (Get Data → OData Feed) with the same service URL. If it connects successfully, this will indicate the issue is likely related to the SAP_DWC_01.mez custom connector rather than the Datasphere service.

If the issue still occurs, please ask the SAP team to verify the KEY_DATE parameter definition, OData exposure settings, and any recent authorization or metadata changes for that analytical model. You may also try connecting with a different date value or without the parameter to check if the parameter handling is causing the error. Please share the outcome and we’ll be happy to assist further.

Thank you

[v-kpoloju-msft]

Hi @Ynr0225, 

Just checking in to see if the issue has been resolved on your end. If the earlier suggestions helped, that’s great to hear! And if you’re still facing challenges, feel free to share more details happy to assist further.

Thank you.

[Ynr0225]

Hello @v-kpoloju-msft ,

I tried to connect with OData feed native connector in Power BI desktop and received below error

[v-kpoloju-msft]

Hi @Ynr0225, 

Thank you for trying the OData Feed connector and sharing the screenshot. The error “The given URL neither point to an OData service or a feed” usually indicates that the URL being used is not the actual OData service endpoint. While the browser may still return JSON, Power BI requires the correct OData service root or entity feed URL to recognize it as a valid OData source.

Could you please check with your SAP Datasphere team to confirm that the URL being used is the correct OData service endpoint for the analytical model and that the model is exposed for OData access? Once the correct service root URL is provided, please try connecting again using the OData Feed connector in Power BI Desktop. If the issue persists, feel free to share the endpoint format (masking sensitive details) so we can review it further.

Thank you again for using the Microsoft Fabric Community Forum.

[v-kpoloju-msft]

Hi @Ynr0225, 

Just checking in to see if the issue has been resolved on your end. If the earlier suggestions helped, that’s great to hear! And if you’re still facing challenges, feel free to share more details happy to assist further.

Thank you.