Hi LK
It has been a while and I am writing to see how things are going with this issue. Have you had a chance to check the replies provided? Any update would be appreciated.
Warm Regards
Published Outlook Calendar Not Working - GetAnonymousCalendarSessionData Failed
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(288, 44%, 37%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EL%3C/text%3E%3C/svg%3E)
LK
20
Reputation points
We have a public calendar and have been using an Outlook calendar as a means to publish it on the web for folks to see events. Somewhat recently (not sure when), that published calendar stopped working. We are now getting this error:
UTC Date: [Moderator note : PII Removed] Client Id: [Moderator note : PII Removed] Session Id: [Moderator note : PII Removed] Client Version: [Moderator note : PII Removed] BootResult: [Moderator note : PII Removed] Back Filled Errors: None err: Error: GetAnonymousCalendarSessionData failed: Failed to execute [Moderator note : PII Removed] on 'Response': Unexpected end of [Moderator note : PII Removed] input esrc: [Moderator note : PII Removed] et: [Moderator note : PII Removed] estack: Error: GetAnonymousCalendarSessionData failed: Failed to execute [Moderator note : PII Removed] on 'Response': Unexpected end of [Moderator note : PII Removed] input at H [Moderator note : PII Removed] at [Moderator note : PII Removed]
This has also happened last summer (then it didn't work for a few weeks, not only with us but with many other people too). That apparently had to do with some update.
I've tried lots of things to try to fix it that I saw on this forum, like unpublishing/republishing, but nothing seems to work.
Help! A shared calendar like this is really not useful if you can't count on it.
PII : Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.
Outlook | Web | Outlook.com | Calendar
Answer accepted by question author
-
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(208, 57.99999999999999%, 30%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EAN%3C/text%3E%3C/svg%3E)
Alice-N 4,125 Reputation points Microsoft External Staff Moderator2025-12-07T07:53:01.83+00:00
2 additional answers
Sort by: Most helpful
-
Alice-N 4,125 Reputation points Microsoft External Staff Moderator
2025-12-06T10:40:33.94+00:00 Dear LK
Thank you for reaching out to the Microsoft Q&A Community. I understand you are having a problem with your published Outlook calendar showing the error GetAnonymousCalendarSessionData failed. I am happy to assist you. Please try the following steps:
- Verify Anonymous Sharing Policy
- If you are using Microsoft 365 or Exchange Online, ensure the sharing policy includes Anonymous access. In Exchange Admin Center, go to Organization > Sharing, and confirm that anonymous calendar publishing is allowed.
- For further guidance : Publish Calendar option is missing from Calendar - Exchange | Microsoft Learn
- Adjust Published Calendar URL
- Change the published link from https://outlook.live.com to https://outlook.com. This may resolve display issues after recent updates.
- Clear Browser Cache or Test in Private Mode
- Cached scripts can cause JSON parsing errors. Clear your browser cache or open the published link in an incognito/private window.
- Check Microsoft 365 Service Health Dashboard
- Sign in to Service Health Dashboard and verify if there is an active advisory for Outlook calendar publishing.
- Re-publish After Policy Confirmation
- After confirming anonymous sharing is enabled, unpublish and re-publish the calendar to refresh permissions.
- Contact Microsoft Support if Issue Persists If none of the above resolves the problem, open a support ticket and reference the error details.
- Visit this website: Contact - Microsoft Support
- Type your problems in the search box there. ( For example, Contact support.)
- Now click on Get Help and select Contact Support below.
- Go to the Products & Services tab and choose the Outlook category
- On the Category tab, choose based on your actual problem, such as cannot sign in.
- Go to Confirm.
- Choose to chat with a support representative or request a call back.
Note: The support contact team only works at certain times, so if the last window shows that it's unavailable, try opening it again the next day. If you prefer phone support, you can leave a phone number. This way, they can call you and help you.
If the answer is helpful, please click Accept Answer and kindly upvote it. If you have extra questions about this answer, please click Comment.
Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
- Verify Anonymous Sharing Policy
-
LK 20 Reputation points
2025-12-08T17:13:42.0733333+00:00 Thank you Alice-N. I tried all of your steps, nothing worked so far. Even contacting Microsoft didn't work now unfortunately. I'll try again tomorrow.