Your block is very complicated and you have given very little description on how it should work. I don't have the free time to donate figuring out how you have set everything up. You say that "when I stretch the block with a "standaard" interior to 900 width it should switch automatically to the NA_DE/EN/FR/NL visibility dependant on the nation selection." I assume that you are saying that when the BC linear parameter is stretched to 900 units, that should trigger a change to the visibility state based on the language setting. That said, I don't see where the BC parameter is on any lookup table, nor it is on the block properties table. Explain exactly what you believe should make that change in visibility.
There is no reason to use list values for the selection memory storage. It does absolutely nothing helpful, it's a waste of time/effort, and can actually cause problems that are difficult to diagnose.
If you are using linear parameters solely for the memory storage of the lookup selection, then there is no need to add any action to them.
Why are you using a double lookup for Language? I believe it should be just a single lookup. Again, don't use a list on the parameter.
