Hi Tarbat,
Sorry for the late response. The Dutch islands (Waddeneilanden) and most Zeeuwse Islands are not in the standard outline files supplied bij Airnav. As Rod Bearden (reply204) kindly has mentioned, you have to download third party software to make them visible. This is not an Airnav 5.0 issue, it has been an issue all the time. These islands (for example the island of Texel with the local airport EHTX is floating around in the Northsea, the island is missing) were never there on the base map over the years. In fact around 15% of The Netherlands was never there on these maps. Odd, and a bit of a bother, or Airnav is way ahead of time... (I know I can make use of OpenStreetMap/Satellite layers, but this is not my issue....)
Frank