Insert Group Calendar WebPart causing error

Terry Naudé 26 Reputation points

A user reported this error when trying to add a group Calendar in a SharePoint Online Modern Page

1- From any page on the site, Edit.
2- Hit Plus sign in between section to add a web part.
3- Select "Group Calendar"
4- Error!

Error Message:
Something went wrong
If the problem persists, contact the site administrator and give them the information in Technical Details.

When you click on TECHNICAL DETAILS:
Something went wrong
If the problem persists, contact the site administrator and give them the information in Technical Details.TECHNICAL DETAILS
Cannot read property 'offset' of undefined
TypeError: Cannot read property 'offset' of undefined
at t._setRegionalSetting (
at t.onInit (
at t._onInViewport (
at new Promise (<anonymous>)
at t._internalFirstTimeRender (
at e._renderWebPart (

What I tried

  1. I created a calendar on the site as it had none but this made no difference. (so not an issue related to not having calendar)
  2. Trying adding the group calendar WebPart on a new page within the site causes the same problem. (so not page related)
  3. Tried adding webpart on another site in the same tenancy and did not get the error. (so must be site related)
  4. I have checked site features and compared to a site where it does work found no differences.

I have been looking at this for too long and thought I would put it out here in case I am missing something obvious.


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Accepted answer
  1. Niclas Rakowsky 86 Reputation points

    I was able to fix the same error by adjusting the site collection time zone to match the time zone of the group calendar.

    2 people found this answer helpful.

1 additional answer

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  1. Emily Du-MSFT 39,606 Reputation points Microsoft Vendor

    @Terry Naudé

    Have you added some custom codes on the page?

    Whether some users or all users who add the group calendar web part on this site collection page will report an error?

    If some users occur error, please remove these users then re-add them into site collection.

    If an Answer is helpful, please click "Accept Answer" and upvote it
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