I just tried to import the skos vocab to describe links between three different concepts ( I need the classes skoas: broader/narrower/broaderTransitive and narrowerTransitive. Here is the page i filled in and the mistake message above:
No class or properties found. Are you sure you used the correct namespace URI ?
I filled in this way :
Vocabulary URI : https://www.w3.org/2009/08/skos-reference/skos.html
Préfix : SKOS
Spacename URI : https://www.w3.org/2009/08/skos-reference/skos.html
Label : SKOS
I am a beginner in Omeka-S , so sorry in advance if is an easy mistake to correct but I cannot find solutions.