Denis, 1. from isc.Eng.Hov import * . Result: ImportError: No module named isc.Eng.Hov 2. import HovEngine. Result: ImportError: No module named HovEngine 3. import isc.Eng.Hov.HovEngine. Result: ImportError: No module named isc.Eng.Hov.HovEngine 4. from isc.Eng.Hov.HovEngine import *. Result ImportError: No module named isc.Eng.Hov.HovEngine I don't know where the mistake could be hidden. As I see from object browser the namespace is HovEngine. [image: unspecified.jpg] Then, what's wrong? On Mon, Oct 17, 2016 at 2:12 PM Denis Akhiyarov <denis.akhiyarov@gmail.com> wrote: Hi Artem, If clr.FindAssembly("isc.Eng.Hov") and clr.AddReference("isc.Eng.Hov") are working fine, then you need to `import HovEngine`, but not `import isc.Eng.Hov`. This is assuming isc.Eng.Hov is assembly name, and HovEngine is namespace name. Thanks, Denis On Mon, Oct 17, 2016, 12:08 AM Artem Zhukov <green.azhukov@gmail.com> wrote: Hello all, please help me to resolve the following problem. I was trying a lot of things (see 1) and still didn't get it. There is also a project on freelancer for that (see 2): 1. http://stackoverflow.com/questions/40037684/adding-reference-to-net-assembly... 2. https://www.freelancer.com/contest/Write-some-Software-867914.html -- ARTEM ZHUKOV | HVAC/Mech.Engineer | Building Performance Engineer | Sustainability Engineer | HVAC TPM | M: +420 774 081 898 <774%20081%20898> _________________________________________________ Python.NET mailing list - PythonDotNet@python.org https://mail.python.org/mailman/listinfo/pythondotnet _________________________________________________ Python.NET mailing list - PythonDotNet@python.org https://mail.python.org/mailman/listinfo/pythondotnet -- ARTEM ZHUKOV | HVAC/Mech.Engineer | Building Performance Engineer | Sustainability Engineer | HVAC TPM | M: +420 774 081 898