Background

I have a C# application developed using Visual Studio 2013 which interacts with Passolo 2015 (build 15.1.453.0) projects.

I've recently taken delivery of a new laptop running Windows 8.1 Enterprise which required new installs of VS 2013 and Passolo Professional 2015 (installed via Admin user). 

It's creating an exception when it creates the PassoloApp object using this line of code:

PassoloU.PassoloApp passolo = new PassoloApp()

The exception is:
Exception: Retrieving the COM class factory for component with CLSID {6F0A6A19-F203-463E-8702-CE795A5BE307} failed due to the following error: 80080005 Server execution failed (Exception from HRESULT: 0x80080005 (CO_E_SERVER_EXEC_FAILURE)).

Questions

Given I've created many similar C# applications in the past with no problems I'm wondering if this is an installation issue?

I've checked this registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PASSOLO.Application.15\CLSID
Value = {6F0A6A19-F203-463E-8702-CE795A5BE307}

Should I also be seeing this registry key (with subkeys):

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{6F0A6A19-F203-463E-8702-CE795A5BE307}

Is this the reason for the exception?

Any help greatly appreciated.

Mark