Skip to main content

Notifications

Community site session details

Community site session details

Session Id :
Power Automate - Building Flows
Answered

Office 365 Groups - Send HTTP request V2 failing: {"hideAttendees": true}

(0) ShareShare
ReportReport
Posted on by 142

Hi,

 

I've created a Flow that invites new starters (New Attendee) to a companywide calendar event organised in Teams. It's supposed to set the hideAttendees parameter to true to prevent everyone getting emailed the invite when only a single attendee is added. I've used these two guides to give me a starting point and then my own knowledge to build this out:

Update Event and Hide Attendees - DamoBird365

Efficient Event Management: Update Attendees list with Graph API in Power Automate - YouTube

 

The Flow hooks into Office 365 Groups, grabs an event filtered by subject and checks to see if the value in the JSON body of hideAttendees is set to true (last step in the below graphic).

 

(Start of Flow)

JustAPACreator_0-1709224792097.png

 

This is the JSON step:

JustAPACreator_1-1709225212397.png

 

and the value {"hideAttendees": false} is contained within the Output body:

JustAPACreator_2-1709225397610.png

 

I've then created a Condition to check if that value is set to true already (due to errors when adding more Attendees if it was). This part begins where (Start of Flow) finishes:

JustAPACreator_3-1709225495450.png

 

This Condition evaluates correctly (where {"hideAttendees": false} is set) and passes down the If no side:

JustAPACreator_1-1709291962483.png

Whereby it errors with:

JustAPACreator_2-1709292061123.png

 

{
  "error": {
    "code""ErrorInvalidRequest",
    "message""The OData request is not supported."
  }
}
 
Status Code 405
 
Using GET works (obviously) but using PATCH doesn't seem to work to change the value "hideAttendees" from false to true.
 
Can anybody help, please? Happy to provide any further information or screenshots.
 
Mark.
  • CU31011410-0 Profile Picture
    142 on at
    Re: Office 365 Groups - Send HTTP request V2 failing: {"hideAttendees": true}

    Hi,

     

    Thank you so much, your answer was spot on:

     

    Amended:

    JustAPACreator_1-1709294622764.png

    And voila!

    JustAPACreator_0-1709294591014.png

     

    I'm so grateful to you, @Expiscornovus and this community @ManishSolanki for jumping in and trying to help.

     

    Mark.

  • CU31011410-0 Profile Picture
    142 on at
    Re: Office 365 Groups - Send HTTP request V2 failing: {"hideAttendees": true}

    Using POST created a new meeting twice:

    JustAPACreator_0-1709294135406.png

  • ManishSolanki Profile Picture
    15,085 Super User 2025 Season 1 on at
    Re: Office 365 Groups - Send HTTP request V2 failing: {"hideAttendees": true}

    Hi @JustAPACreator 

     

    Pls use POST method.

     

     

  • Verified answer
    Expiscornovus Profile Picture
    31,732 Most Valuable Professional on at
    Re: Office 365 Groups - Send HTTP request V2 failing: {"hideAttendees": true}

    Hi @JustAPACreator,

     

    In your setup I see you are using a $filter query parameter in the URI of that PATCH request. Normally that request expects an eventid. The format should be like the below

    /groups/{id}/events/{id}

     

    That method is used to update a single event:

    https://learn.microsoft.com/en-us/graph/api/event-update?view=graph-rest-1.0&tabs=http

     

    Can you remove that $filter part and use the eventid of your parse json instead?

Under review

Thank you for your reply! To ensure a great experience for everyone, your content is awaiting approval by our Community Managers. Please check back later.

Helpful resources

Quick Links

Michael Gernaey – Community Spotlight

We are honored to recognize Michael Gernaey as our June 2025 Community…

Congratulations to the May Top 10 Community Leaders!

These are the community rock stars!

Announcing the Engage with the Community forum!

This forum is your space to connect, share, and grow!

Leaderboard >