2
           
            
                
     
    
    Open the file modules/news/include/functions.php in a texteditor and look for the function 
news_getWysiwygForm.
In this function the paths to the editors are defined.
Check if the paths correspond with your installation of the editors.
Probably some paths have to be changed, ie:
 /class/wysiwyg/formwysiwygtextarea.php  
should probably be:
 /class/xoopseditor/formwysiwygtextarea.php  
The path to tinyeditor should be correct.