I created an installer script for SemanticForms, everything should work but it did not. I could not find what the problem was so I asked MinuteElectron to help me out. After some research he found that it had to do with the order in which the SemanticMediaWiki and the SemanticForms were loaded; they are loaded in alphabetical order so the SemanticForms came in first.
I have created a hack to get around this; I have renamed the SemanticForms.settings.php to xSemanticForms.settings.php. The documentation is clear; Semantic MediaWiki has to be installed and in this way MediaWiki is aware of this. Adding an x does the trick.
I wonder if this is one of those temporary solutions that will prove to be permanent.