So I noticed that the the ‘top’ domain references
http://www.exampledomain.nl/wp-content/uploads/dynamic_avia/enfold.css

And the others from the multi domain:
http://www.exampledomain.nl/de/files/dynamic_avia/enfold.css
http://www.exampledomain.nl/en/files/dynamic_avia/enfold.css
http://www.exampledomain.nl/nl/files/dynamic_avia/enfold.css

It is observed that ‘wp-content/uploads’ gets substituded by ‘files’ directory

I created a workarround by copying the dynamic_avia directectory to:
nl/files/dynamic.avia
de/files/dynamic.avia
en/files/dynamic.avia
in html-root
It works but it is unclear why ‘wp-content/uploads’ gets substituded by ‘files’