COM object can't be created when I upgrade client .Net Framework version

I have .net console application and com object I want to instantiate via:

var t = Type.GetTypeFromProgID("myProgID");
var o = Activator.CreateInstance(t);

everything works fine when client platform is .net framework 3.5开发者_如何学C, but crashes when I upgrade version number to 4.0 with

Retrieving the COM class factory for component with CLSID {xxx-xxx} failed due to the following error: 80004005 (E_FAIL)?

COM object is built with .Net Framework 3.5

What shall I do to make my Com object usable?

Thank you in advance!

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The error message is hopeless, you'll need to debug the COM server to see what is going wrong. If you don't have the source code for it then you may get something out of the trace you get from SysInternals' ProcMon. Realistically, you need help from the component vendor or author.

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The answer was - Avira Antivirus !

Another problem with Antivirus is described here: (SEH)Exception initializing Nlog

I deinstalled that and found out that everything became ok !

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Seems like the GUID changed. Are you sure that it's looking for the correct GUID, and that the COM object is registered with that GUID?