These issue could be caused by a cache problem Those units might already been build. But because your cache is full your browser pulls an old image from your cache and displays these page. If you refresh your page you might see that those units where build. or that you  really are out of resources. My advice  clear your cache. 

If the problem still persist then please send a ticket 

https://plariumsupport.zendesk.com/hc/en-us/requests/new