Outlook 2010

Moss1234

Outlook 2010 problem, When inviting recipients and clicked on scheduling grayed out as per the attachment.
Please help

panm

Close Outlook and launch it by typing outlook /cleanfreebusy in Run field (Win+R key).
Try steps in this link You experience issues in Outlook when you try to configure free/busy information or when you try to delegate information

Claymoore

Modern versions of Outlook and Exchange use the availability service, part of Exchange Web Services, to query mailboxes for free/busy information. The EWS URL is returned from the Autodiscover lookup. You can use the Remote Connectivity Analyzer to test EWS lookups. Just a warning - you could be going down a rabbit hole of DNS entries, External and Internal URL settings, and certificates.

For example, I had a client that had multiple divisions who did not configure the External URL on their WebServices Virtual Directories - it had to be done from powershell and wasn't visible in the 2007/2010 EMC. Free/Busy worked fine internally, but broke when trying from a mailbox in their Office 365 tenant because that was an external request.

You can check the EWS virtual directory URLs with this command:
Get-WebServicesVirtualDirectory | format-table server,internalurl,externalurl -auto

Chivalry1

The big question is this problem occurring for all users or a few mailboxes?

Also I see you are running the Outlook client via Citrix. Make sure you the Citrix server can appropriately reach the CAS where EWS services are running. Make sure you have an DNS auto discover record that is resolvable by the client. Make sure you have the appropriate SAN name on your certificate that matches your auto discover url. [Get-WebServicesVirtualDirectory | format-table server,internalurl,externalurl -auto]. I hope this helps.

N2IT

Sometimes the user is apart of some groups that had AD accounts that have been disabled. However there is still remains of that profile in the group they are associated with. If that add account is still there but removed. It will look very cryptic, it can do crazy things to the users calendar.