Symptoms

The issue occurs during the installation via the command line, when trying to use FineReader Engine 12 (via IEngineLoader interface) receiving this error:

Error: "Retrieving the COM class factory for component with CLSID {...} failed due to the following error: <...> Class not registered (Exception from HRESULT: <...>))

Cause

Loading the Engine object by means of COM into the current process using the InprocLoader object requires the registration of FREngine.dll on an end user's computer.

Resolution

Please try to register FREngine.dll using the following command line:
regsvr32 /s /n /i:"<path to the Inc folder>" "<path to FREngine.dll>"