Exchange setup fails on Step 10 of 14: Mailbox role: Mailbox service

Clean load of 2012 R2, Prepped schema and AD.

Exchange setup fails with the below:

Error:
The following error was generated when "$error.Clear();
          if ($RoleIsDatacenter -ne $true -and $RoleIsDatacenterDedicated -ne $true)
          {
          if (Test-ExchangeServersWriteAccess -DomainController $RoleDomainController -ErrorAction SilentlyContinue)
          {
          $sysMbx = $null;
          $name = "SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c}";
          $dispName = "Microsoft Exchange";
          Write-ExchangeSetupLog -Info ("Retrieving mailboxes with Name=$name.");
          $mbxs = @(Get-Mailbox -Arbitration -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1 );
          if ($mbxs.Length -eq 0)
          {
          Write-ExchangeSetupLog -Info ("Retrieving mailbox databases on Server=$RoleFqdnOrName.");
          $dbs = @(Get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
          if ($dbs.Length -ne 0)
          {
          Write-ExchangeSetupLog -Info ("Retrieving users with Name=$name.");
          $arbUsers = @(Get-User -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
          if ($arbUsers.Length -ne 0)
          {
          Write-ExchangeSetupLog -Info ("Enabling mailbox $name.");
          $sysMbx = Enable-Mailbox -Arbitration -Identity $arbUsers[0] -DisplayName $dispName -database $dbs[0].Identity;
          }
          }
          }
          else
          {
          if ($mbxs[0].DisplayName -ne $dispName )
          {
          Write-ExchangeSetupLog -Info ("Setting DisplayName=$dispName.");
          Set-Mailbox -Arbitration -Identity $mbxs[0] -DisplayName $dispName -Force;
          }
          $sysMbx = $mbxs[0];
          }

          # Set the Organization Capabilities needed for this mailbox
          if ($sysMbx -ne $null)
          {
          # We need 1 GB for uploading large OAB files to the organization mailbox
          Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
          set-mailbox -Arbitration -identity $sysMbx -UMGrammar:$true -OABGen:$true -GMGen:$true -ClientExtensions:$true -MailRouting:$true -MessageTracking:$true -PstProvider:$true -MaxSendSize 1GB -Force;
          }
          else
          {
          Write-ExchangeSetupLog -Info ("Cannot find arbitration mailbox with name=$name.");
          }
          }
          else
          {
          Write-ExchangeSetupLog -Info "Skipping creating E15 System Mailbox because of insufficient permission."
          }
          }
        " was run: "Database is mandatory on UserMailbox.".

Error:
The following error was generated when "$error.Clear();
          if ($RoleIsDatacenter -ne $true -and $RoleIsDatacenterDedicated -ne $true)
          {
          if (Test-ExchangeServersWriteAccess -DomainController $RoleDomainController -ErrorAction SilentlyContinue)
          {
          $sysMbx = $null;
          $name = "SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c}";
          $dispName = "Microsoft Exchange";
          Write-ExchangeSetupLog -Info ("Retrieving mailboxes with Name=$name.");
          $mbxs = @(Get-Mailbox -Arbitration -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1 );
          if ($mbxs.Length -eq 0)
          {
          Write-ExchangeSetupLog -Info ("Retrieving mailbox databases on Server=$RoleFqdnOrName.");
          $dbs = @(Get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
          if ($dbs.Length -ne 0)
          {
          Write-ExchangeSetupLog -Info ("Retrieving users with Name=$name.");
          $arbUsers = @(Get-User -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
          if ($arbUsers.Length -ne 0)
          {
          Write-ExchangeSetupLog -Info ("Enabling mailbox $name.");
          $sysMbx = Enable-Mailbox -Arbitration -Identity $arbUsers[0] -DisplayName $dispName -database $dbs[0].Identity;
          }
          }
          }
          else
          {
          if ($mbxs[0].DisplayName -ne $dispName )
          {
          Write-ExchangeSetupLog -Info ("Setting DisplayName=$dispName.");
          Set-Mailbox -Arbitration -Identity $mbxs[0] -DisplayName $dispName -Force;
          }
          $sysMbx = $mbxs[0];
          }

          # Set the Organization Capabilities needed for this mailbox
          if ($sysMbx -ne $null)
          {
          # We need 1 GB for uploading large OAB files to the organization mailbox
          Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
          set-mailbox -Arbitration -identity $sysMbx -UMGrammar:$true -OABGen:$true -GMGen:$true -ClientExtensions:$true -MailRouting:$true -MessageTracking:$true -PstProvider:$true -MaxSendSize 1GB -Force;
          }
          else
          {
          Write-ExchangeSetupLog -Info ("Cannot find arbitration mailbox with name=$name.");
          }
          }
          else
          {
          Write-ExchangeSetupLog -Info "Skipping creating E15 System Mailbox because of insufficient permission."
          }
          }
        " was run: "Database is mandatory on UserMailbox.".