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maxquerystringlength in custom connector

Good morning,


I'm currently tring to create a custom connector for Hubspot CRM, but i'm getting a C# error

enter image description here


because of a too long query string.


This is not easy to understand the error, but here are the step.


I configure a custom Connector with an Oauth 2.0 connection


Scheme : https
Host :
Base url : /

Client ID and Client Secret :  from the app created with the hubspot interface.

Authorization url :

Token anf refresh URL :

Scope : contacts


this gave me a redirection URL as expected.

When I try a new connection (with test), i have a popup wich ask me for hubspot connexion, and i can log in correctly, but then i get the error about the query.

This seems not to be an hubspot issue, as the error is in C# from an Azure URL, and as when a provide a wrong Scope or a Scope for which i don't have access Hubspot provide an error from there website.

Does anyone have an idea to solve this error ?





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Re: maxquerystringlength in custom connector

Cat Happy

I don't know if these links can help you, I am a newbie to the Web api.


I feel that this is not a problem on the Flow side. Maybe you should go to the C# community to make a turn.Smiley Very Happy






Level: Powered On

Re: maxquerystringlength in custom connector

Thanks for your answer,


I know this is a C# problem, but i don't have access to the source code of Microsoft Flow.


I will report this problem as a bug since no one has an idea,


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Re: maxquerystringlength in custom connector

The resulting JWT token appears in the URL and exceeds the query limit.  We cant change the grant type so we are sort of hosed.

Level: Powered On

Re: maxquerystringlength in custom connector

This is on the flow side I think - Flows seem to use the authorization_flow grant type once the user is authenticated and grants consent the resulting token is returned in the URL when the redirect is called.  This causes the query string to be too long.

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