When trying to use the Interop COM interface and create an Application instance, I always get the following error message (as if there is no MultiTerm installed on the system):

The COM class factory for the component with CLSID {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} could not be retrieved due to the following error: 80040154 Class not registered (exception of HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).
at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.Activator.CreateInstance(Type type)
at RWS_MultiTerm_Interop_Test.frmMain.InitMultiTerm() in <PATH TO SOURCE FILE>:line 228.

A MultiTerm repair installation, as well as a complete reinstallation, has already been attempted. Likewise, testing has been done on multiple systems and with multiple MultiTerm versions, which are:

• MultiTerm 2021 SR2 - 16.2.1.1044
• MultiTerm 2022 SR1 - 17.1.1.2185

• Microsoft Windows 7 Enterprise version 6.1.7601 Service Pack 1 Build 7601
• Microsoft Windows 10 Pro Version 10.0.19045 Build 19045
• Microsoft Windows 11 Pro Version 10.0.22621 Build 22621

We have also been in contact with a developer from RWS who sadly is currently not able to respond to us and our business contact at RWS urged us to create another post here to further this issue and hopefully a resolution forward.

With the mentioned RWS developer we were in contact with, he reviewed a sample application we provided and asked us to try out the following sample by RWS (which ultimately led to the same error message above): https://github.com/RWS/Sdl-Community/tree/bb990fb00165398395d10bfbb4d233ef4f4a4e5d/Code%20samples/MultiTermSearchExample