I wanted to update this post with my experience.
I had the same problem trying to run the HCW in my environment.
We have 3 Public Folder DB's on different ex 2010 Mailbox Servers. the the PF content is replicated to all the DB's
The public folders were originally migrated/replicated from exchange 2003
There is no exchange 2003 in the environment anymore. Its all native exchange 2010 now
There are no problems with the public folder infrastructure. Everything is working fine.
There is no trace of any 'legacy' exchange 2003 leftovers from exchage 2003. Everything was removed following the MS documentation.
I was unable to run HCW, it would fail with: "ValidateConfiguration execution failed: Configure Legacy Exchange Support"
Log files show the HCW trying to get-publicfolders on my mailbox servers.
It succeeds on the first server, and then fails on the next one it tries
[7/30/2012 21:36:42] INFO:Running command: Get-PublicFolderDatabase -Server 'MBX-A-00'
[7/30/2012 21:36:42] INFO:Cmdlet: Get-PublicFolderDatabase --Start Time: 30/07/2012 22:36:42.
[7/30/2012 21:36:42] INFO:Cmdlet: Get-PublicFolderDatabase --End Time: 30/07/2012 22:36:42.
[7/30/2012 21:36:42] INFO:Cmdlet: Get-PublicFolderDatabase --Processing Time: 46.884.
[7/30/2012 21:36:42] INFO:Running command: Get-PublicFolder -Identity '\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY' -Server 'MBX-A-00' -Recurse ''
[7/30/2012 21:36:42] INFO:Cmdlet: Get-PublicFolder --Start Time: 30/07/2012 22:36:42.
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolder --End Time: 30/07/2012 22:36:43.
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolder --Processing Time: 906.424.
[7/30/2012 21:36:43] INFO:Running command: Get-PublicFolderDatabase -Server 'VEXMBX-A-01'
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolderDatabase --Start Time: 30/07/2012 22:36:43.
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolderDatabase --End Time: 30/07/2012 22:36:43.
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolderDatabase --Processing Time: 62.512.
[7/30/2012 21:36:43] INFO:Running command: Get-PublicFolder -Identity '\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY' -Server 'MBX-A-01' -Recurse ''
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolder --Start Time: 30/07/2012 22:36:43.
[7/30/2012 21:36:43] ERROR:System.Management.Automation.RemoteException: No existing 'PublicFolder' matches the following Identity: '\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY'. Make sure that you specified the correct 'PublicFolder' Identity and that you have the necessary permissions to view 'PublicFolder'.
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolder --End Time: 30/07/2012 22:36:43.
[7/30/2012 21:36:43] INFO:Cmdlet: Get-PublicFolder --Processing Time: 62.512.
[7/30/2012 21:36:43] INFO:Disconnected from On-Premises session
[7/30/2012 21:36:43] INFO:Disconnected from Tenant session
[7/30/2012 21:36:43] ERROR:Updating hybrid configuration failed with error 'Subtask ValidateConfiguration execution failed: Configure Legacy Exchange Support
at Microsoft.Exchange.Management.Hybrid.Engine.ExecuteTask(TaskBase taskBase, TaskContext taskContext)
I could - as an administrator - run the same get-publicfolder command in powershell, and confirm the foders exist and can be enumerated on this same server on which the failure was occuring
Get-PublicFolder -Identity '\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY' -Server 'MBX-A-01' -recurse
This command would return the '\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY' folder and its children. It would work find when targeting any of my exchange mailbox servers. No problem
nonetheless the HCW would not get past this point.
I tried to run that same powershell command, running as the 'on-premise' user account used in the HCW. It would work on 2 of my DB's but consistently fail on the same server mentioned in my logs. Output was as follows:
Get-PublicFolder -Identity '\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY' -Server 'MBX-A-01' -Recurse
No existing 'PublicFolder' matches the following Identity: '\NON_IPM_SUBTREE\SCHEDULE+ FREE BUSY'. Make sure that you specified the correct 'PublicFolder' Identity and that you have the necessary permissions to view 'PublicFolder'.
+ CategoryInfo : NotSpecified: (0:Int32) [Get-PublicFolder], MapiOperationException
+ FullyQualifiedErrorId : 1ACB800A,Microsoft.Exchange.Management.MapiTasks.GetPublicFolder
I confirmed the user account was a member of 'organisational management'
It didnt matter what additional rights this user was granted - i tried domain admin, enterprise admin, builtin administrators... - it would always fail.
Further testing revealed that this user account could not actually enumerate ANY public folders on this specific PF database on this 1 mailbox server
Get-PublicFolder -Identity '\' -Server 'MBX-A-01' -Recurse
No existing 'PublicFolder' matches the following Identity: '\'. Make sure that you specified the correct 'PublicFolder' Identity and that you have the necessary permissions to view 'PublicFolder'.
+ CategoryInfo : NotSpecified: (0:Int32) [Get-PublicFolder], MapiOperationException
+ FullyQualifiedErrorId : C0789D04,Microsoft.Exchange.Management.MapiTasks.GetPublicFolder
As it started tto look like permissions, i checked and compared all of the administrative permissions on ALL the public folder DB's with poershell.
Thepermissions were identical on all my public folder db's on all my mailbox servers. There were no differences at all. and certainly no explicit deny rights. Nothing that would explain why the get-publicfolder command would fail.
In the end - out of sheer desperation - i mailbox enabled this user.
This user was not mailbox enabled on prem. There was nothing in any of the documentation that indicated this requirement.
After i mailbox enabled the user, the commands were able to execute. I could enumerate all public folders in all DB's successfully as this user.
Now - i dont understand whats going on here at all. From my perspective it should not be necessary to be mailbox enabled in order to be able to enumerate public folders...
...and - even if that were the case, why would it fail only on 1 specific PF DB and. Surely it should fail on all of them? I do not have answers to these questions.
I have a case open with Office 365 escalation team on this. I will wait for a response as to whats actually going on here. But from my experience working with office 365 support escalation - i may be waiting quite some time. It took me 5 days just to get through their escalation process to speak to someone who was suitably qualified to be able to understand this problem, and not ask me to do stupid / dangerous stuff in my envionrment.
OFFICE 365 Support - YOU NEED TO GET YOUR ACT TOGETHER - YOUR ESCALATION PROCESS IS THE WORST IVE SEEN, AND THE RESPONSE TIMES ARE OUTRAGEOUS FOR A PRODUCT THAT IS SUPPOSED TO BE "ENTERPRISE" CLASS
but for anyone out there having a similar problem - try my steps. Its not dangerous to mailbox enable a user, to see if it clears your problem.