Re: user cannot share his calender

Hi headrush1111,

In terms of the issue only occurred on Outlook client and it worked smoothly on Outlook Web App. The issue should be caused by a client side issue. Based on the situation, I suggest repairing the user’s Office installation to see if any progresses. The following steps are for your reference.

1. Click Start > Control Panel > Programs and Features.
2. Click the Office program you want to repair, and then click Change.
3. Click Repair > Continue. You might need to restart your computer after the repair is complete.

Thanks,
Maggie Li