WHMCS Troubleshooting Troubleshoot the Support System Troubleshoot and resolve Department Not Found errors. Troubleshoot and resolve issues with email importing retrieving the same email replies multiple times. Troubleshoot and resolve issues with DirectAdmin sending piped email replies twice. Troubleshoot and resolve The system blocked a potential email loop. (WHMCS 8.4 and later) or Blocked Potential Email Loop (WHMCS 8.3 and earlier) errors. Troubleshoot and resolve last request failed: invalid SASL argument errors. Troubleshoot and resolve Local Delivery Failed errors. Troubleshoot and resolve Logon failure: unknown user name or bad password errors.