The CMAgent_debug.log shows the following error:

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  [05/27 11:03:41 10020|52][    Msg], _EnModuleInitEx: --> notify Module_Attach [En_Utility.cpp|1877]
  ...
  [05/27 11:04:54 10020|676][FnInOut], pszURL(/ControlManager/ClientCGI/cgiDelegate.dll), pszServer(172.26.6.50), uServerPort(443), pszServerUserName() [Easycurl.cpp|320]
  [05/27 11:04:54 10020|676][ Msg], m_pszURL = https://172.26.6.50:443/ControlManager/ClientCGI/cgiDelegate.dll [Easycurl.cpp|362]
  ...
  [05/27 11:04:55 10020|676][ Msg], CEnrollCommandSenderCallback::HandleResult: ResultFile(D:\Program Files (x86)\Trend 
Micro\OfficeScan\PCCSRV\CMAgent\command\1558926222_000002_Logon_c404912aa10d-40539e0c-f520-7d07-ddbb_result_18467) [AgentHandler.cpp|575]

  [05/27 11:04:55 10020|676][ Msg], CAgentSenderCallback::GetSendResult : (ERR) server error code (-15202) [ServerResult.cpp|52]
  [05/27 11:04:55 10020|676][ Msg], CEnrollCommandSenderCallback::HandleResult: (-1063) = GetSendResult() [AgentHandler.cpp|580]
  [05/27 11:04:55 10020|676][ Fail], CEnrollCommandSenderCallback::HandleResult: Guid(c404912aa10d-40539e0c-f520-7d07-ddbb) m_enumActionType(3) 
nReturnMessage(-1063) [AgentHandler.cpp|595]
  ...
  [05/27 11:04:56 10020|52][   Fail], Cause: Agent is called to shut down. [.\Registrator.cpp, 119] [En_Utility.cpp|1916]
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You can find lots of error messages like the following in TMCM_cgiDelegate.log:

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  05-22 16:20:21,01d68:0301c,[Error], *** RelayDataByMsgBuffer(): CException = (10060) A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
  [cd_ISAPIDelegate.cpp|1133]
  --------cut----------

From SystemInfo_NetworkStatus.txt of the TMCM server, it shows that there are lots of connections with the TIME_WAIT status:

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   TCP    127.0.0.1:20001            127.0.0.1:51844            TIME_WAIT              0
    TCP    127.0.0.1:20001            127.0.0.1:51848            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:51863            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:51878            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52031            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52033            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52068            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52069            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52073            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52173            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52178            TIME_WAIT             0
    TCP    127.0.0.1:20001            127.0.0.1:52197            TIME_WAIT             0
  --------cut----------

Access the TMCM server and do the following:

1. Reduce the client TCP/IP socket connection timeout value from the default value of 240 seconds:
   1. Start Registry Editor.
       

      Always back up the whole registry before making any modifications. Incorrect changes to the registry can cause serious system problems.
   2. Browse to this registry hive: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters.
   3. Create a new REG_DWORD value named "TcpTimedWaitDelay".
   4. Set the value to "30".
2. Extend the Socket Port number by opening Command Prompt with admin privileges and launching the following command:

   netsh int ipv4 set dynamic tcp start=25000 num=30000

3. Reboot the machine.
4. Try to register the OfficeScan server to the TMCM server again.