Error when trying to open application through API using C# example file

Hi!

I'm trying to run Mathcad Prime 9.0 through API. I downloaded the C# example solution and trying to open the application by pressing the button "Start Mathcad Prime".

https://support.ptc.com/help/mathcad/r9.0/en/index.html#page/PTC_Mathcad_Help/API/example-2_ms_dev_studio.html#

However, I get the following error:

Problem to connect Mathcad Prime: Retrieving the COM class factory for component with CLSID {A00E8B95-D415-433F-A04E-D298A54A7BB7} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).

I've been googling and using AI for few hours now to fix the problem, but nothing seems to solve the issue. Is there anyone here that could help? Thank you so much!