When opening remote console "Object reference not set" 0x800706BA is seen or The RPC server is unavailable

Issue
When attempting to open a remote console, you see the following error message:

Puremessage

Object reference not set
0x800706BA

Enterprise Console 4.0
Sophos Control Center 4.0

The RPC server is unavailable.

----- [outer exception] -----
-- error: 0x800706BA
-- facility: Win32

at struct IUnknown *__cdecl bl::SystemEnviroment::CreateInstanceOnServer(const struct _GUID &,const struct _GUID &,class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> >)
at void __thiscall bl::CReusingManagementServiceClientBroker::CreateCoreServices(void)
at __thiscall bl::CReusingManagementServiceClientBroker::CReusingManagementServiceClientBroker(const class bl::CReusingManagementServiceClientBroker &)
at void __thiscall bl::CServerBrokerRegistrar::SetBroker(const class bl::CServerBrokerBase &) throw(...)
at int __cdecl Run(int,enum bl::ConsoleType::Type)
at int __stdcall wWinMain(struct HINSTANCE__ *,struct HINSTANCE__ *,wchar_t *,int)



This can happen when:

• attempting to launch a remote PureMessage console (in a clustered installation, or where the message in-box and message delivery servers are different)
• attempting to launch a remote Enterprise Console
• attempting to launch a remote Sophos Control Center

Known to apply to the following Sophos product and version
PureMessage for Microsoft Exchange 3.0.2
Enterprise Console 4.0
Sophos Control Center 4.0

Operating system
Windows Server 2008

What to do

This error means that the RPC service was not available. The most likely reason is that there is a conflict with the Windows firewall.

To test this, turn off the Windows firewall and try opening the console again. If this works:

1. On the Windows server on which the console(s) is/are installed, open the 'Windows Firewall Settings'.
2. Switch to the 'Exceptions' tab.
3. Select the 'Add program...' button.
4. Select the console executable file in the installation directory, for example:
   C:\Program Files\Sophos\PureMessage\bin\beacon.exe
   C:\Program Files\Sophos\Enterprise Console\EnterpriseConsole.exe
   C:\Program Files\Sophos\Sophos Control Center\SBEConsole.exe
5. Select the 'Change Scope...' button and select a scope that is appropriate to your network requirements.
6. Accept the change.
7. If the Server component of PureMessage is installed, then repeat for the 'savexsrvc.exe' program. This is located in the same folder as 'beacon.exe'.
   
   If the Management Server of Enterprise Console is installed (and for Sophos Control Center), do this for the 'MgntSvc.exe' file, installed in the same folder as the console executable.
8. Select the 'Add port...' button.
9. For PureMessage, enter the port number used by the 'Quarantine Digest' website, by default this will be 8081 TCP but may be different on each server.
10. Accept the change.