I have several users that over the last 1-2 months increasingly have experienced that their Outlook wont sync. All of them then experience as message in the bottom of the Outlook screen that says "Need password", but if you click it, you just get a quick blink of a white screen, and then it disappears.

While the issue is present for the users, it is not possible for them to create a new Outlook profile, as it wouldn't connect to the mailbox. I had luck with just rebooting my own computer, that fixed the issue for me, but only until the next day. Other users had bigger problems getting it to work.

The issue apparently seems to be an implementation on "Web Account Manager" (WAM) in Office/Windows. The solution is to set below registry key to 1 in below path.

Path: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity
Key: DisableADALatopWAMOverride (DWORD)

There is a bit more information on the error on below links. As said, the issue is resolved with above registry fix, but it obviously isn't optimal, and preferably it would be fixed by a software patch, either for Windows or Office.

https://support.microsoft.com/en-us/help/4025962/you-can-t-sign-in-after-you-update-to-office-2016-build-16-0-7967-or-a
https://www.reddit.com/r/Office365/comments/7kklt2/autodiscover_issue_on_outlook_2016_o365_exchange/
https://community.spiceworks.com/topic/2025536-outlook-2016-365-keeps-asking-for-credentials?page=3

In an Office 365 Group calendar you can create a new meeting invite and uncheck the ‘send an invitation to the group’ check box. As expected, this will stop anyone in the group receiving the invite notification.

However, if you need to make any updates to that event (it doesn’t matter what update you make) and click save, a notification will be sent to all members in the group. In addition to this, the Group will also add the calendar event to the personal calendar of the individual who has made the update.

This is not an intuitive user experience.

Three parts to this proposed solution:

1. Change the experience to ensure that the calendar event respects the initial setup upon creation i.e. if the ‘send an invitation to the group’ check box is unchecked, remain this way even if the event is updated and don't send notifications.

2. When adding additional members to the event ensure the ‘send an invitation to the group’ check box is not greyed out and we can make the choice to check or uncheck.

3. Furthermore, can the ‘send an invitation to the group’ be unchecked by default.

People in the world, both admins and users, are constantly asking whether new features Microsoft has announced as on the way or rolling out are deployed to their tenant yet. This often results in a lot of confusion and probably support cases and questions into Microsoft asking these types of questions.

We could solve this by building some sort of "Is this feature deployed to my tenant yet?" tool. This tool would very simply authenticate the person checking via Azure Active Directory, and then return a simple result for the feature you are checking on. Results could be:

- Yes
- Targeted Release Only
- No

It would also be nice if IT Admins could provide a small bit of text/guidance for users in case they come across a feature where the answer is Yes, but the user does not have access. This could point them towards some sort of Support function, request process, etc so IT has a better idea of the needs of their users.

As of now, Outlook can not synch / cache Mailboxes that are shared to an other Outlook User, if the Mailbox has more than 500 Folders. This Limitation should be increased.
In my case the Mailbox of the CEO has more than 500 Subfolders, because he Files a lot in his structure, like CEO's of Financial Companies used to do. He has to assistants and since we migrated all Mailboxes to Office 365, the Assistants can not access his Mailbox in Cached Mode. This is important for the Assistants!
It is described here:
https://support.microsoft.com/en-us/kb/3115602
But it worked before on an Exchange 2010 Server, so why should a CEO accept this limitation when moving from an old Exchange 2010 Server to a new Office 365 Exchange Online Server?

Disabling Group Policy from Office 365 Business users doesn't make a lot of sense to me. A lot of smaller- to medium-sized businesses which have an IT point person who does more than just IT, rely on tools like Group Policy to keep their users running cleanly and uniformly. While larger enterprises use Group Policy to eliminate having to perform the same customization on thousands of devices, small business use the same thing, not to save time managing thousands of devices, but to centralize efforts and increase efficiency when resources are scarce. I was disappointed to learn that all of my GPOs from before 365 are now entirely invalidated, especially after "joining up" in full and subscribing to Office 365, and after migrating from our on-prem. Exchange server to Exchange Online. It feels like a bit of a slap in the face, actually.