Just try by selecting the value to create an object for each row in the given Import action drop-down in the configuration page of the excel importer. It will allow creating an object, hence it will work.
Hope it helps.
In the excel importer module atleast one attribute need to be key , by seeing ur image i think none of the attribute hasn’t be set to key , can you check on it.
Yes, I’m using one attribute as a key (if you don’t do it mendix will show you a pop up message). However I save it and close the page correctly. But then when I try to show that object in a list, this list appears empty.
Can you check the Console for possible errors or warnings while saving the template.