Error:
The following error was generated when "$error.Clear(); 
          $maxWait = New-TimeSpan -Minutes 8
          $timeout = Get-Date;
          $timeout = $timeout.Add($maxWait);
          $currTime = Get-Date;
          $successfullySetConfigDC = $false;

          while($currTime -le $timeout)
          {
            $setSharedCDCErrors = @();
            try
            {
              Set-SharedConfigDC -DomainController $RoleDomainController -ErrorVariable setSharedCDCErrors -ErrorAction SilentlyContinue;
              $successfullySetConfigDC = ($setSharedCDCErrors.Count -eq 0);

              if($successfullySetConfigDC)
              {
                break;
              }
              Write-ExchangeSetupLog -Info ("An error ocurred while setting shared config DC. Error: " + $setSharedCDCErrors[0]);
            }
            catch
            {
              Write-ExchangeSetupLog -Info ("An exception ocurred while setting shared config DC. Exception: " + $_.Exception.Message);
            }

            Write-ExchangeSetupLog -Info ("Waiting 30 seconds before attempting again.");
            Start-Sleep -Seconds 30;
            $currTime = Get-Date;
          }

          if( -not $successfullySetConfigDC)
          {
            Write-ExchangeSetupLog -Error "Unable to set shared config DC.";
          }
        " was run: "System.Exception: Unable to set shared config DC.
   at Microsoft.Exchange.Configuration.Tasks.Task.WriteError(Exception exception, ErrorCategory category, Object target, Boolean reThrow, String helpUrl)
   at Microsoft.Exchange.Configuration.Tasks.Task.WriteError(Exception exception, ErrorCategory category, Object target)
   at Microsoft.Exchange.Management.Deployment.WriteExchangeSetupLog.InternalProcessRecord()
   at Microsoft.Exchange.Configuration.Tasks.Task.<ProcessRecord>b__b()
   at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)".

Hi,

Verify if you can successfully reach DC from Exchange server, and port 3268 is not blocked by local firewalls
Verify if the DC you are reaching - has also GC function enabled.
Restart the installation Exchange server, check if Event Viewer shows Event 2080, restart CU7 installation.