Mailbox service erroring out on Exchange 2016 installation

Hello,

I am in the process of migrating a 2010 Exchange Server running on Windows Server 2008 R2 Standard (Service Pack 3, update roll up 21)  to a 2016 Exchange server (CU 12) running on Windows Server 2016.
I completed all of the prerequisites and proceeded to install the Exchange 2016 role. Once I got to step 11 out of 14, it errored out on the mailbox role with the following message.

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{e0dc1c29-89c3-4034-b678-e6c29d823ed9}";
          $dispname = "Microsoft Exchange";
          $mbxs = @( get-mailbox -arbitration -Filter {name -eq $name} -IgnoreDefaultScope -resultSize 1 );
          if ( $mbxs.length -eq 0)
          {
          $dbs = @(get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
          if ($dbs.Length -ne 0)
          {
          $arbUsers = @(get-user -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
          if ($arbUsers.Length -ne 0)
          {
          $sysMbx = enable-mailbox -Arbitration -identity $arbUsers[0] -DisplayName $dispname -database $dbs[0].Identity;
          }
          }
          }
          else
          {
          if ($mbxs[0].DisplayName -ne $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)
          {
          Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
          set-mailbox -Arbitration -identity $sysMbx -UMDataStorage:$true -Force;

          # No RetentionPolicy assigned to E-Discovery arbitration mailbox currently, we need to set it here.
          # This can be remove after BUG(O15#2555914) is fixed.
          if ($sysMbx.RetentionPolicy -eq $null )
          {
          $arbitrationRetentionPolicy = @(Get-RetentionPolicy -DomainController $RoleDomainController | where {$_.Name -eq 'ArbitrationMailbox'});
          set-mailbox -Arbitration -identity $sysMbx -RetentionPolicy $arbitrationRetentionPolicy[0].Identity -Force;
          }
          }
          else
          {
          Write-ExchangeSetupLog -Info ("Cannot find E-discovery arbitration mailbox with name=$name.");
          }
          }
          else
          {
          write-exchangesetuplog -info "Skipping creating Discovery Arbitration Mailbox because of insufficient permission."
          }
          }
        " was run: "Microsoft.Exchange.Data.DataValidationException: 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{e0dc1c29-89c3-4034-b678-e6c29d823ed9}";
          $dispname = "Microsoft Exchange";
          $mbxs = @( get-mailbox -arbitration -Filter {name -eq $name} -IgnoreDefaultScope -resultSize 1 );
          if ( $mbxs.length -eq 0)
          {
          $dbs = @(get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
          if ($dbs.Length -ne 0)
          {
          $arbUsers = @(get-user -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
          if ($arbUsers.Length -ne 0)
          {
          $sysMbx = enable-mailbox -Arbitration -identity $arbUsers[0] -DisplayName $dispname -database $dbs[0].Identity;
          }
          }
          }
          else
          {
          if ($mbxs[0].DisplayName -ne $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)
          {
          Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
          set-mailbox -Arbitration -identity $sysMbx -UMDataStorage:$true -Force;

          # No RetentionPolicy assigned to E-Discovery arbitration mailbox currently, we need to set it here.
          # This can be remove after BUG(O15#2555914) is fixed.
          if ($sysMbx.RetentionPolicy -eq $null )
          {
          $arbitrationRetentionPolicy = @(Get-RetentionPolicy -DomainController $RoleDomainController | where {$_.Name -eq 'ArbitrationMailbox'});
          set-mailbox -Arbitration -identity $sysMbx -RetentionPolicy $arbitrationRetentionPolicy[0].Identity -Force;
          }
          }
          else
          {
          Write-ExchangeSetupLog -Info ("Cannot find E-discovery arbitration mailbox with name=$name.");
          }
          }
          else
          {
          write-exchangesetuplog -info "Skipping creating Discovery Arbitration Mailbox because of insufficient permission."
          }
          }
        " was run: "Microsoft.Exchange.Data.DataValidationException: Database is mandatory on UserMailbox.
   at Microsoft.Exchange.Configuration.Tasks.Task.ThrowError(Exception exception, ErrorCategory errorCategory, Object target, String helpUrl)
   at Microsoft.Exchange.Configuration.Tasks.Task.WriteError(Exception exception, ErrorCategory category, Object target, Boolean reThrow)
   at Microsoft.Exchange.Configuration.Tasks.DataAccessTask`1.Validate(TDataObject dataObject)
   at Microsoft.Exchange.Configuration.Tasks.SetTaskBase`1.InternalValidate()
   at Microsoft.Exchange.Configuration.Tasks.SetRecipientObjectTask`3.InternalValidate()
   at Microsoft.Exchange.Management.Common.SetMailEnabledRecipientObjectTask`3.InternalValidate()
   at Microsoft.Exchange.Management.RecipientTasks.SetUserBase`3.InternalValidate()
   at Microsoft.Exchange.Management.RecipientTasks.SetMailboxBase`3.InternalValidate()
   at Microsoft.Exchange.Management.RecipientTasks.SetMailbox.InternalValidate()
   at Microsoft.Exchange.Configuration.Tasks.Task.<ProcessRecord>b__91_1()
   at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)".

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{e0dc1c29-89c3-4034-b678-e6c29d823ed9}";
          $dispname = "Microsoft Exchange";
          $mbxs = @( get-mailbox -arbitration -Filter {name -eq $name} -IgnoreDefaultScope -resultSize 1 );
          if ( $mbxs.length -eq 0)
          {
          $dbs = @(get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
          if ($dbs.Length -ne 0)
          {
          $arbUsers = @(get-user -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
          if ($arbUsers.Length -ne 0)
          {
          $sysMbx = enable-mailbox -Arbitration -identity $arbUsers[0] -DisplayName $dispname -database $dbs[0].Identity;
          }
          }
          }
          else
          {
          if ($mbxs[0].DisplayName -ne $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)
          {
          Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
          set-mailbox -Arbitration -identity $sysMbx -UMDataStorage:$true -Force;

          # No RetentionPolicy assigned to E-Discovery arbitration mailbox currently, we need to set it here.
          # This can be remove after BUG(O15#2555914) is fixed.
          if ($sysMbx.RetentionPolicy -eq $null )
          {
          $arbitrationRetentionPolicy = @(Get-RetentionPolicy -DomainController $RoleDomainController | where {$_.Name -eq 'ArbitrationMailbox'});
          set-mailbox -Arbitration -identity $sysMbx -RetentionPolicy $arbitrationRetentionPolicy[0].Identity -Force;
          }
          }
          else
          {
          Write-ExchangeSetupLog -Info ("Cannot find E-discovery arbitration mailbox with name=$name.");
          }
          }
          else
          {
          write-exchangesetuplog -info "Skipping creating Discovery Arbitration Mailbox because of insufficient permission."
          }
          }
        " was run: "Microsoft.Exchange.Data.DataValidationException: 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{e0dc1c29-89c3-4034-b678-e6c29d823ed9}";
          $dispname = "Microsoft Exchange";
          $mbxs = @( get-mailbox -arbitration -Filter {name -eq $name} -IgnoreDefaultScope -resultSize 1 );
          if ( $mbxs.length -eq 0)
          {
          $dbs = @(get-MailboxDatabase -Server:$RoleFqdnOrName -DomainController $RoleDomainController);
          if ($dbs.Length -ne 0)
          {
          $arbUsers = @(get-user -Filter {name -eq $name} -IgnoreDefaultScope -ResultSize 1);
          if ($arbUsers.Length -ne 0)
          {
          $sysMbx = enable-mailbox -Arbitration -identity $arbUsers[0] -DisplayName $dispname -database $dbs[0].Identity;
          }
          }
          }
          else
          {
          if ($mbxs[0].DisplayName -ne $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)
          {
          Write-ExchangeSetupLog -Info ("Setting mailbox properties.");
          set-mailbox -Arbitration -identity $sysMbx -UMDataStorage:$true -Force;

          # No RetentionPolicy assigned to E-Discovery arbitration mailbox currently, we need to set it here.
          # This can be remove after BUG(O15#2555914) is fixed.
          if ($sysMbx.RetentionPolicy -eq $null )
          {
          $arbitrationRetentionPolicy = @(Get-RetentionPolicy -DomainController $RoleDomainController | where {$_.Name -eq 'ArbitrationMailbox'});
          set-mailbox -Arbitration -identity $sysMbx -RetentionPolicy $arbitrationRetentionPolicy[0].Identity -Force;
          }
          }
          else
          {
          Write-ExchangeSetupLog -Info ("Cannot find E-discovery arbitration mailbox with name=$name.");
          }
          }
          else
          {
          write-exchangesetuplog -info "Skipping creating Discovery Arbitration Mailbox because of insufficient permission."
          }
          }
        " was run: "Microsoft.Exchange.Data.DataValidationException: Database is mandatory on UserMailbox.
   at Microsoft.Exchange.Configuration.Tasks.Task.ThrowError(Exception exception, ErrorCategory errorCategory, Object target, String helpUrl)
   at Microsoft.Exchange.Configuration.Tasks.Task.WriteError(Exception exception, ErrorCategory category, Object target, Boolean reThrow)
   at Microsoft.Exchange.Configuration.Tasks.DataAccessTask`1.Validate(TDataObject dataObject)
   at Microsoft.Exchange.Configuration.Tasks.SetTaskBase`1.InternalValidate()
   at Microsoft.Exchange.Configuration.Tasks.SetRecipientObjectTask`3.InternalValidate()
   at Microsoft.Exchange.Management.Common.SetMailEnabledRecipientObjectTask`3.InternalValidate()
   at Microsoft.Exchange.Management.RecipientTasks.SetUserBase`3.InternalValidate()
   at Microsoft.Exchange.Management.RecipientTasks.SetMailboxBase`3.InternalValidate()
   at Microsoft.Exchange.Management.RecipientTasks.SetMailbox.InternalValidate()
   at Microsoft.Exchange.Configuration.Tasks.Task.<ProcessRecord>b__91_1()
   at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)".



I have been reading online that a fix is to delete the system mailbox and then re-create it on the existing Exchange 2010 server.  When I go into Active Directory, the System Mailboxes are all in a disabled state. This is a production server. What impact could this have on the end users and mail flow, if any? Is there any other way to resolve this without deleting anything that may be "less riskier"? I need to get Exchange 2016 installed as soon as possible so I can begin migrating the mailboxes to it. Any advice / help is appreciated. Thanks!