Outlook cannot save changed permissions, mainly because delegated access is not working. The problem can also be caused by network access provider restrictions and various add-ons. This error prevents the user from changing calendar permissions and sharing the calendar with other users.
This is a common problem that occurs due to minor technical issues in the Outlook application. This problem does not mean that the problem is with the hardware itself. Be sure to bring your Outlook credentials with you before you start, as they are required. Many users encounter this error on their system. If you want to fix this error, here are some steps.