Exchange 2013 install fails on Step 10 Mailbox Role: Mailbox Service

Hello,

I am installing Exchange 2013 onto a Server 2012 server, we are currently running Exchange 2007 in a organisation of three other sites. We are the first site to upgrade to Exchange 2013 but we do not hold the Default OAB, when we run the Exchange 2013 install it fails at Step 10 Mailbox Role: Mailbox Service with this error:

Error:
The following error was generated when "$error.Clear();
          if (!$RoleIsDatacenter -and !$RoleIsDatacenterDedicated)
          {
            $createNewOab = $false;
            $oabName = $null;
            $oabAddressList = $null;
            $oabVdirs = $null;
            $oabGlobalWebDistribution = $false;
            $oabConfiguredAttributes = $null;

            Write-ExchangeSetupLog -Info ("Looking for an existing default OAB");
            $defaultOab = Get-OfflineAddressBook -DomainController:$RoleDomainController | where {$_.IsDefault};
            if ($defaultOab -ne $null)
            {
              Write-ExchangeSetupLog -Info ("Found a default OAB: " + $defaultOab.Name + "; checking its version");
              if ($defaultOab.ExchangeVersion.CompareTo([Microsoft.Exchange.Data.ExchangeObjectVersion]::Exchange2012) -lt 0)
              {
                $e15Oab = Get-OfflineAddressBook -DomainController:$RoleDomainController | where {$_.ExchangeVersion.CompareTo([Microsoft.Exchange.Data.ExchangeObjectVersion]::Exchange2012) -eq 0};
                if ($e15Oab -eq $null)
                {
                  Write-ExchangeSetupLog -Info ("Existing OAB is Exchange 2010 or older; will create a new OAB");
                  $createNewOab = $true;
                  $oabName = $defaultOab.Name + " (Ex2013)";
                  $oabAddressList = $defaultOab.AddressLists;
                  $oabGlobalWebDistribution = $defaultOab.GlobalWebDistributionEnabled;
                  $oabConfiguredAttributes = $defaultOab.ConfiguredAttributes;
                }
                else
                {
                  Write-ExchangeSetupLog -Info ("Already has an existing Exchange 2013 OAB:" + $e15Oab.Name + "; will not create a new OAB");
                }
              }
              else
              {
                Write-ExchangeSetupLog -Info ("Existing OAB is Exchange 2013 or newer; will not create a new OAB");
              }
            }
            else
            {
              Write-ExchangeSetupLog -Info ("Did not find a default OAB; will create one");
              $createNewOab = $true;
             
              $oabName = [Microsoft.Exchange.Data.Directory.SystemConfiguration.OfflineAddressBook]::DefaultName;
              $nonDefaultOabWithDefaultName = Get-OfflineAddressBook $oabName -DomainController:$RoleDomainController -ErrorAction SilentlyContinue | where {$_.IsDefault -eq $false};
              if ($nonDefaultOabWithDefaultName -ne $null)
              {
                $createNewOab = $false;
                Write-ExchangeSetupLog -Warning `
                  ("Offline address book " + `
                  $nonDefaultOabWithDefaultName.Name + `
                  " already exists: " + `
                  $nonDefaultOabWithDefaultName.DistinguishedName + `
                  ". Use administrative tools to change it to default OAB.");
              }

              $allGals = @(Get-GlobalAddressList -DomainController:$RoleDomainController | where {$_.IsDefaultGlobalAddressList});
              if ($allGals -eq $null -or $allGals.Count -eq 0)
              {
                $createNewOab = $false;
                Write-ExchangeSetupLog -Warning `
                  ("Couldn't find the default global address list. The default offline address book can't be created.");
              }
              elseif ($allGals.Count -gt 1)
              {
                $createNewOab = $false;
                Write-ExchangeSetupLog -Warning `
                  ("Found " + $allGals.Count + " default global address lists. You can have only one default global address list in your organization. The default offline address book will not be created.");
              }
              else
              {
                $oabAddressList = $allGals[0];
                Write-ExchangeSetupLog -Info ("OAB will be based on default GAL: " + $oabAddressList.Name);
              }
            }

            if ($createNewOab)
            {
              if ($oabGlobalWebDistribution -eq $false)
              {
                $currentAdSiteDn = (Get-ExchangeServer $RoleFqdnOrName -DomainController:$RoleDomainController).Site.DistinguishedName;
                $allOabVdirs = @(Get-OabVirtualDirectory -ADPropertiesOnly -DomainController:$RoleDomainController);
                $e15MinimumServerVersion = New-Object Microsoft.Exchange.Data.ServerVersion([Microsoft.Exchange.Data.Directory.SystemConfiguration.Server]::E15MinVersion);
                if ($allOabVdirs -ne $null -and $allOabVdirs.Count -gt 0)
                {
                  foreach ($oabVdir in $allOabVdirs)
                  {
                    if ([Microsoft.Exchange.Data.ServerVersion]::Compare($oabVdir.AdminDisplayVersion, $e15MinimumServerVersion) -gt 0)
                    {
                      $oabVdirSiteDn = (Get-ExchangeServer $oabVdir.Server -DomainController:$RoleDomainController).Site.DistinguishedName;
                      if ($oabVdirSiteDn -eq $currentAdSiteDn)
                      {
                        $oabVdirs = $oabVdir;
                        break;
                      }
                      elseif ($oabVdirs -eq $null)
                      {
                        $oabVdirs = $oabVdir;
                      }
                    }
                  }
                }

                if ($oabVdirs -ne $null)
                {
                  Write-ExchangeSetupLog -Info ("OAB will be distributed to OAB virtual directory " + $oabVdirs.Name);
                }
                else
                {
                  Write-ExchangeSetupLog -Info ("Could not find any OAB virtual directories; OAB will be configured without distribution.");
                }
              }

              try
              {
                Write-ExchangeSetupLog -Info ("Creating new default OAB.");
                $newOab = New-OfflineAddressBook `
                  -Name $oabName `
                  -AddressLists $oabAddressList `
                  -VirtualDirectories $oabVdirs `
                  -GlobalWebDistributionEnabled $oabGlobalWebDistribution `
                  -IsDefault $true `
                  -DomainController:$RoleDomainController;
              }
              catch [Microsoft.Exchange.Data.Directory.ADObjectAlreadyExistsException]
              {
                Write-ExchangeSetupLog -Warning ("Tried to create new default OAB but the object already exists; it may have been created by another instance of setup.");
              }

              if ($oabConfiguredAttributes -ne $null)
              {
                Write-ExchangeSetupLog -Info ("Setting OAB ConfiguredAttributes to: " + $oabConfiguredAttributes);
                Set-OfflineAddressBook $newOab -ConfiguredAttributes $oabConfiguredAttributes -DomainController:$RoleDomainController;
              }
            }
          }
        " was run: "Address list or global address list "\Default Global Address List" was not found. Please make sure you typed the identity correctly.".

Can someone please advise what might be causing this?

Thanks