Will not work always, or better to say, might not catch the reason, on the contrary will work fine without a problem, as you don't always need to RegisterClass to use it or create it at runtime.
This might well be the case. But in this case the solution is very simple:
You only have to switch the components one by one or in groups from designtime to runtime. This way you can easily find the component, which is causing the error.
You are you there
, i missed this idea, still hooking is faster and less code, in case OP is lazy like me.