Error (431): Request Header Fields Too Large

[PowerNooby]

I am also encountering error message "(431): Request Header Fields Too Large" when I select Opportunity Object from Power Query (from Power BI Desktop and Excel).

I had reviewed the posts on similar error message but the solutions don't apply to my situation because I didn't get to select the data fields before the error message appears.  The recommended solutions to reduce the number of columns is not applicable.

Below is the screenshot of the error message taken from Power Query.  Redacted the data fields name for confidentialty reason.

[danielcontente]

Hi, did you manage to solve it?
I am having the same issues...

[PowerNooby · Accepted solution]

This issue is caused by too many data fields created in a Salesforce object.  A workaround is not to refresh data when connected to the object.  After selecting the Salesforce object, click at "Transform Data" button in Power Query.  Then select "Choose Columns" button to select the applicable columns in the object.  Filter data if necessary before click at "Refresh Preview" button to refresh data.  Click at "Close & Load" button to close the Power Query Editor.

[Anonymous]

Hi @PowerNooby ,

Based on the information you provided, it seems that the error message is related to the size of the request header fields. One possible solution is to increase the size limit of the request header fields. You can try to modify the registry settings to increase the size limit of the request header fields.

Here are the steps to modify the registry settings:

1. Open the Registry Editor by typing "regedit" in the Start menu search box and selecting the "Registry Editor" app.
2. Navigate to the following registry key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\Parameters
3. Right-click on the "Parameters" key and select "New" > "DWORD (32-bit) Value".
4. Name the new value "MaxFieldLength" and set its value to a decimal number that represents the maximum size of the request header fields in bytes. For example, if you want to set the maximum size to 64 KB, set the value to 65534.
5. Right-click on the "Parameters" key again and select "New" > "DWORD (32-bit) Value".
6. Name the new value "MaxRequestBytes" and set its value to a decimal number that represents the maximum size of the entire request in bytes. For example, if you want to set the maximum size to 128 MB, set the value to 134217728.
7. Close the Registry Editor and restart your computer.

Please note that modifying the registry settings can be risky and may cause system instability or other problems if not done correctly. Therefore, it is recommended that you create a backup of your registry before making any changes.

Best Regards,

Stephen Tao

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.           

[PowerNooby]

Thank you Stephen for responding to my request for assistance. Unfortunately, this solution is not feasible as our IT Support would not allow us to make modifications to registry.

[SteveLilley]

Hello, I know it's been a long timebut just sharing this in case others are hunting for an answer. We also had a salesforce object with 700+ fields and got the same error.. This worked for us as we could cherry pick the fields we wanted (and did not need 700+)

Import as normal and you will have a set of steps that fail at step 2.. Leave step 1 intact and change step two as below in the advance editor to "cherry pick" the fields you want. We found you can have up to 698 before this falls over but if you only need a subset of the fields then this works.

let

    Source = Salesforce.Data("https://login.salesforce.com/", [ApiVersion=48]),

    #"Removed Other Columns" = Table.SelectColumns(

Source{[Name="Name_of_table"[Data],

{

"Name",

"RecordTypeId"

})

in

    #"Removed Other Columns"