There is currently a known issue with Microsoft Outlook in downloading and synchronising from iCal links, affecting the use of iCalendar links generated from PracSuite. Specifically, users attempting to synchronise with an existing iCalendar or import their 'iCal' link for the first time will be asked to enter a username and password:
However, entering the requested credentials will fail or result in an error message.
Please note this is a known issue with the desktop version of Microsoft Outlook, following changes made by Microsoft in March 2022. Please refer to the following Microsoft article for more information, which includes a workaround as detailed below: You can't add an Internet calendar to Outlook 2019, Outlook 2016, and Outlook for Office 365.
Workaround
To work around this issue, use Outlook Web App (OWA). OWA doesn't have this authentication header behavior. Therefore, it will successfully open the Internet calendar that you want to add.
To use OWA to add the calendar, follow these steps:
Sign in to OWA.Switch to the Calendar module.Select the Add calendar menu.Select the From internet option.Provide the URL and an optional calendar name.Select Save.
If this workaround is not successful, please contact Microsoft for further assistance. Alternatively, you may wish to try different calendar software until the issue is resolved by Microsoft.