Upgrading Exchange 2010 SP1 to SP3…got this error

Ladies and/or gentlemen,

I am currently in the end stages of a migration from Exchange 2003 to Exchange 2010. At this point, the exchange servers are in a state of co-existence wherein the majority of exchange users' mailboxes have not yet been migrated over to the 2010 server.
In fact, I've only migrated two accounts over to the Exch2010 server. The first of these was my domain admin mailbox, then the mailbox for one of my end-users. I was unable to access my migrated end-user's mailbox via OWA. More specifically, all of my non-migrated users who are still on Exch2003 are not having any issues accessing their mail via OWA but any migrated users are presented with a very vague "Bad Command" error after attempting to log in to the 2010 OWA. (By that I mean that they put in "mail/exchange" in their browser and are successfully redirected to the OWA login for the new Exch2010 server. After putting in their credentials, they get the "Bad Command" error mentioned above. I created a new "testuser" on the new Exch2010 server and got the same message when attempting to connect to their mailbox.

I've requested support from the Microsoft Exchange professionals to help with this issue but they indicated that they wouldn't be able to help me unless I upgrade my 2010 Exchange Server to SP3 which would place it within Microsoft's support realm, whereas Exch2010 SP1 is no longer supported.

I downloaded the SP3 patch and ran into an error while upgrading the Mailbox Server role. The error is as follows:

Summary: 15 item(s). 12 succeeded, 1 failed.
Elapsed time: 00:33:02


Organization Preparation
Completed

Elapsed Time: 00:09:54


Preparing Setup
Completed

Elapsed Time: 00:00:02


Stopping Services
Completed

Elapsed Time: 00:00:25


Languages
Completed

Elapsed Time: 00:00:00


Remove Exchange Files
Completed

Elapsed Time: 00:01:45


Preparing Files
Completed

Elapsed Time: 00:00:00


Copy Exchange Files
Completed

Elapsed Time: 00:00:47


Language Files
Completed

Elapsed Time: 00:05:38


Restoring services
Completed

Elapsed Time: 00:00:02


Languages
Completed

Elapsed Time: 00:02:54


Hub Transport Role
Completed

Elapsed Time: 00:04:19


Client Access Role
Completed

Elapsed Time: 00:03:17


Mailbox Role
Failed

Error:
The following error was generated when "$error.Clear();
          if (!$RoleIsDatacenter)
          {
            $arbUsers = @(get-user -Filter {lastname -eq "MSExchApproval 1f05a927-3be2-4fb9-aa03-b59fe3b56f4c"} -IgnoreDefaultScope -ResultSize 1);
            if ($arbUsers.Length -ne 0)
            {
              $mbxname = $arbUsers[0].name;
              $mbxs = @( get-mailbox -arbitration -Filter {name -eq $mbxname} -IgnoreDefaultScope -resultSize 1 );
              if ( $mbxs.length -eq 0)
              {
                $dbs = @(get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
                if ($dbs.Length -ne 0)
                {
                  enable-mailbox -Arbitration -identity $arbUsers[0] -database $dbs[0].Identity;
                }
              }
            }
          }
        " was run: "The user's Active Directory account must be logon-disabled for linked, shared, or resource mailbox.".

The user's Active Directory account must be logon-disabled for linked, shared, or resource mailbox.
Click here for help... http://technet.microsoft.com/en-US/library/ms.exch.err.default(EXCHG.141).aspx?v=14.3.123.3&e=ms.exch.err.Ex88D115&l=0&cl=cp

Elapsed Time: 00:03:54

After looking at this error, I went to look at the Exchange User properties for my Domain Admin account and got another error message stating that:

"The properties on this object have invalid data. If you click OK, default values will be used instead and will be saved if you do not change them before hitting Apply or OK in the property page. If you click cancel, the object will be displayed read-only and corrupted values will be retained."

I do not get this or any other error if I go to look at my end-user's properties…only on the domain admin account.

After trying to do a bit of research, I came to understand that the process of installing Exchange 2010 SP3 forces all Users and Mailboxes on the 2010 server to be dismounted during the upgrade process. My assumption here is that my domain admin mailbox somehow became corrupted and is now preventing the completion of the Exch2010 SP3 installation…which is…in turn…preventing me from getting support from Microsoft to resolve my migrated users inability to access their mail via OWA.

My gut tells me that I need to delete/recreate my domain admin account's mailbox before I will be able to complete the upgrade to SP3, but I'm not entirely sure how to do that. I suspect that I can do it via ASDIedit but I am hesitant to do anything as "potentially dangerous" as deleting items willy-nilly out of my ADDS infrastructure.

Can anyone provide some guidance or clarity on this situation? This is my first attempt at an Exchange migration and I'm quite nervous about exacerbating the issue at this point.

If needs any more information to help diagnose the source of the problem please let me know and I will comply in every way I know how.

EDIT – Whatever mail might be contained in the domain admin's mail account is completely unimportant. It has never, to my knowledge, been actively used as a means of communication. To delete the mailbox and recreate a new one is my desired course of action, if doing so is the easiest solution to the issue at hand.