Google Big Query Connector - May 25 Release

[Dilbertfan]

Hi All

Wasn't sure whether to post this in Power Query or Desktop as I suppose it could fit in either.

I have been trying to use the Revised Big Query Connector in the May 25 release of PBIDT.  I have put in my Google Organisational Account Credentials and agreed that PBIDT can access my account. 

It then seems to connect:

But when I try to drill down into the data, i get the following error:

I thought that this was a driver error, but i have been told that the new version of the connector does not need a driver when connecting, and I haven't been able to find one for Power BI to Big Query in the ADBC format which i can get installed.

I have a call in with IT about the Network or Proxy issues relating to the HTTP/2 protocol.

Wonder if anyone can point me in the right direction

Thanks in advance for your help

Rich

[v-kpoloju-msft · Accepted solution]

Hi @Dilbertfan, 

Thank you for reaching out to the Microsoft fabric community forum. Also, thanks @Akash_Varuna, for those valuable insights for this thread. I have identified several alternative workarounds that may assist in resolving the thread.

Based on the error you're encountering:
ADBC: Status(StatusCode="Internal", Detail="Bad gRPC response. Response protocol downgraded to HTTP/1.1"),

This relates to the newly introduced Google Big Query connector using ADBC, which was released in Power BI Desktop’s May 2025 update and is currently in Preview. The ADBC-based connector utilizes gRPC over HTTP/2, providing enhanced performance and modern protocol advantages. However, it requires network environments that support HTTP/2. The error suggests that gRPC is reverting to HTTP/1.1, which the new connector does not support, resulting in the failure.

As the connector is currently in Preview, you may option to use the legacy version:

• Go to File > Options and settings > Options > Preview Features
• Uncheck: "Use ADBC-based Big Query connector"
• Restart Power BI Desktop
• This will revert to the previous (ODBC-based) connector, which does not rely on HTTP/2.

 If continuing with the Preview connector: Please ensure the following network conditions: HTTP/2 support is enabled end-to-end. No TLS/SSL inspection or proxy is downgrading HTTP/2 to HTTP/1.1

Whitelist the following domains:

• *.googleapis.com
• bigquery.googleapis.com
• oauth2.googleapis.com

These changes may require assistance from your IT/network team.

Kindly please refer to the below mentioned link for better understanding and more information:
Google Big Query connector - Power Query | Microsoft Learn
Compare gRPC services with HTTP APIs | Microsoft Learn

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 for using Microsoft Community Forum.

[Dilbertfan]

Thank you @v-kpoloju-msft for taking the time to give me a detailed response and will take everything on board.

I know that the bigquery end points are white listed, but not sure about the HTTP/2.  Will look into that - this was the bit that I was unsure of whether it was a driver or network issue, but seemingly the latter.

The reason we are using the new connector is we have always had problems with the legacy connector and never been able to connect properly, despite all end points white listed and correct access permissions.  Even with support from Microsoft we can't get it to access the Big Query datasets - we got further with the new connector; we could at least see the datasets 🙂

[Akash_Varuna]

Hi @Dilbertfan I think it is because of network or proxy settings blocking HTTP/2, required by the new BigQuery connector. Coordinate with IT to whitelist BigQuery endpoints and enable HTTP/2. If unresolved, use the legacy connector as a workaround and ensure Power BI Desktop is up-to-date. Also, confirm your Google account has the necessary BigQuery access permissions.

[Dilbertfan]

Thank you @Akash_Varuna  - appreciate you taking the time to respond.  I know that the bigquery end points are white listed, but not sure about the HTTP/2.  Will look into that.  The reason we are using the new connector is we have always had problems with the legacy connector and never been able to connect properly, depsite all end points white listed and correct access permissions.