Disappering PF and Shared Folders - Common Issue, but the usual fixes are not working.

Question

This is Exchange 2016 On-Prem. Outlook 2016, and 2019 for sure. I know I'm posing in the cloud forum, but there is no On-Prem Exchange category any longer. The common issue? 30 seconds after clients open Outlook, about the time the email/alert notification window pops up, the Public Folders and all shared/deleted mailboxes disappear. Before they disappear, they are accessible, and work properly, then POOF, gone! The usual fixes that don't work (or work for a day or two)? Repair Office, delete and recreate the outlook profile, repair the OST, un-check the download shared folders, switch to online mode (turn off cache), run Outlook in Safe Mode. We also created new public folders and verified they also fall to this issue. I have open a case with Microsoft at the tune of $500. Case number 24155972. Microsoft has been a NO SHOW on this issue. Occasionally chiming in to ask the same 5 questions. Apparently Hafnium has been keeping them busy. So our issue is small potatoes. They have spent some time on it, remoted in, took some info, played around with it, and agree it is baffling as they could not fix it so far. SO it is not the obvious answers. This is an elusive issue. I need the true guru answer here. This server has been running flawlessly for 3 years, then on February 4th, users began having the issue, not all at once, not all on that day, but within a week everyone had eventually had this issue. We find the most useful fix is the recreation of the Outlook profile, it will often bring the Public Folders and Shared Folders back for a time period of a few hours to a few days. We have spent 40% of our time deleting and recreating the profile so people can work. I do not believe it was an update, the last updates to run before this began was a solid three weeks prior. We even applies the latest CU19 in order to try to solve it. I install LOTS of On-Prem Exchange servers, thousands of end users with Outlook Desktop Application. This issue is only happening with one client server and its 75 users. This leads me to believe it is a server issue, but I cannot track it down. Half of me believes Microsoft has boobietrapped the server in hopes we'd make a move to migrate it all to Microsoft 365. I'm reaching out to everyone else because this needs fixed, and as much as I know about Exchange configuration and management, I cannot put my finger on what's happened here. One of you has the magic pill. Please help.

Answer 1

@Anonymous

I noticed that you have opened a case to Microsoft, I would suggest you wait the response from them. They can get more detailed information for troubleshooting.

From this forum, here are my some suggestion to help you to troubleshoot:

1. Whether the client connect to Exchange directly? If there exist intermediate equipment, I would suggest you bypass them, then recreate Outlook profile and check whether is this issue gone.
2. You can also using Get-PublicFolderMailboxDiagnostics command to check whether there exist issue with the public folder.

Based on your description, I think this issue more related with the Network or the hard disk where the database is stored.

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Answer 2

Hi, have you ever found out why this happened? Since today I suddenly have a client with Exchange 2019 onprem and Outlook 2019 that has the exact same problem. It started out of nowhere after everything worked fine for a full year after installing the server. The server is fully Windows updated and Exchange patched. There were no Exchange updates installed when this started happening and I also believe there were no Outlook updates installed as a lot of people, but not all suddenly have this issue. The problem is exactly what you describe, the Public Folders and Shared Mailboxes work just fine and after like 10 seconds, magically, they disappear. When you restart Outlook they are back and disappear again after 10 seconds. When I create a new Outlook profile it seems to work but as nobody knows why this happens I don't like the thought of this coming back again.