Failure in creation of feature class: Unable to create object class extension COM component

I am working with ArcGIS 10.5, installed on-premise, and are developing our feature class in .NET.

I have an issue with registering feature classes. We have created a Feature Class and registered the DLL through “ESRIRegAsm.exe”, and it appears in ArcCatalog:

Trigger appearing image

But when I try to create the Feature Class, I get the following error:

Failed to create feature class. Unable to create object class extension COM Component

Which isn't very helpful, unfortunately.

The odd thing is, that we have another trigger registered on another Feature Class, that works as expected. And the new trigger is based on a copy of the old trigger's code (with changed GUID's).

The steps I have done so far:

1. I have tried to add the feature class to the component category using categories.exe.

2. Registered it using ESRIRegAsm.exe for both Desktop and Engine. Checked that there are .ecfg config files - and there are.

3. Checked that the CLSID's appear in the windows registry.

The essential parts of our trigger source-code can be found here: here.

Any help would be greatly appreciated, as we are stuck on this.

Our issue was that our ID's were wrong in the code. The ClassExtensionCLSID should return the same ID as TriggerExtension has.

Moreover, InstanceCLSID should always return 52353152-891A-11D0-BEC6-00805F7C4268, and should hence not get a new ID.