While working in a hybrid environment most of the users face difficulties as the organization permissions differ from that of user permissions. Users having accounts on both Exchange Online and On-premises Exchange Server have major issues, like when Office 365 users try to open their On-premises calendar it fails to open. So, to fix the Office 365 hybrid calendar sharing information user needs to change the Free/ busy permissions.
When the user tries to open the calendar it shows an error ‘Couldn’t Open the Calendar’ with a detailed message as ‘A connection couldn’t be made with the shared calendar. Remove Calendar and try to add it again or contact the owner and ask to share it again.’ So, we could follow the actions shown in the message or change the permissions.
Causes of Office 365 Hybrid Calendar Error
First, we need to know how the calendar accesses the information, When a user request action the scheduling assistant, functions on the basis of the Organization relationship and avoids user permissions. The permissions that are attached to the default account are checked and act on calendar information free/ busy, time, and other factors. If the calendar permission is set to ‘None’ then it could not display the result.
Fix Calendar Settings in Office 365 for On-premises users
The calendar settings must be changed to ‘Free Busy’. This could be changed by following the steps
- Login to Office 365 account with username and password
- Now go to the calendar and move to properties
- The ‘Calendar Properties’ box will open
- Click on the ‘permissions tab’
- Set the Permission Level to ‘Free /Busy time’ or Free/ Busy time, subject, location
- Set the Read and Write permissions on the calendar and choose ‘Delete Items’ to ‘None’
- Press OK and Close
- Now, the user can see the ‘Free/ Busy’ status in Scheduling Assistant and the calendar too.
Users often face the problem of ‘Office 365 hybrid calendar could not be updated’ or ‘Office 365 free busy not working’. The main reason is that the Calendar default permission is set to ‘None’ or ‘Controller’. This is why the user is unable to see the mailbox calendar too because when the calendar is set to ‘None’ it does not show up any data to the user.
So, this is the free and manual method to access the On-Premise calendar in Office 365. Users can also contact the mailbox administrator and ask to change permissions. Administrators have the option for ‘federated calendar sharing’ which gives full control to the user. Try these methods and solve the calendar sharing problems in Hybrid Environment.