And as you can see from that page, it can be kind of complex to know the moment where to call it. FormCreate might be too early (but I don't really know about UniGUI events).
So if we try without calling it at all it should still fail, but not hang. If that is what happens we can try to put the FlexCelDllInit call in other place.
As mentioned there, we normally call FlexCelDllInit in the GetExtensionVersion event and call the shutdown in TerminateExtension. Probably create/destroy of the form aren't the right place to call it.