submissions-refactor: fix error handling when no grouping is selected
submissions-refactor: fix error handling when no grouping is selected

ealonas/Markus,finnergizer/Markus,jeremygoh/Markus,arkon/Markus,reidka/Markus,jeremygoh/Markus,benjaminvialle/Markus,Lysette/Markus,david-yz-liu/Markus,binuri/Markus,WilsonChiang/Markus,reidka/Markus,arkon/Markus,reidka/Markus,david-yz-liu/Markus,jeremygoh/Markus,david-yz-liu/Markus,wkwan/Markus,melneubert/Markus,arkon/Markus,finnergizer/Markus,melneubert/Markus,arkon/Markus,david-yz-liu/Markus,jeremygoh/Markus,binuri/Markus,wkwan/Markus,benjaminvialle/Markus,wkwan/Markus,melneubert/Markus,finnergizer/Markus,david-yz-liu/Markus,finnergizer/Markus,MarkUsProject/Markus,ealonas/Markus,MarkUsProject/Markus,MarkUsProject/Markus,benjaminvialle/Markus,ealonas/Markus,melneubert/Markus,melneubert/Markus,ealonas/Markus,WilsonChiang/Markus,ealonas/Markus,WilsonChiang/Markus,Lysette/Markus,jeremygoh/Markus,ealonas/Markus,binuri/Markus,wkwan/Markus,WilsonChiang/Markus,arkon/Markus,Lysette/Markus,reidka/Markus,reidka/Markus,wkwan/Markus,wkwan/Markus,Lysette/Markus,reidka/Markus,benjaminvialle/Markus,jeremygoh/Markus,finnergizer/Markus,david-yz-liu/Markus,wkwan/Markus,MarkUsProject/Markus,arkon/Markus,ealonas/Markus,binuri/Markus,jeremygoh/Markus,arkon/Markus,benjaminvialle/Markus,finnergizer/Markus,melneubert/Markus,WilsonChiang/Markus,WilsonChiang/Markus,benjaminvialle/Markus,wkwan/Markus,WilsonChiang/Markus,finnergizer/Markus,Lysette/Markus,binuri/Markus,reidka/Markus,jeremygoh/Markus,david-yz-liu/Markus,binuri/Markus,MarkUsProject/Markus,finnergizer/Markus,MarkUsProject/Markus,WilsonChiang/Markus,Lysette/Markus,ealonas/Markus,jeremygoh/Markus,reidka/Markus,MarkUsProject/Markus,binuri/Markus,david-yz-liu/Markus,arkon/Markus,Lysette/Markus,melneubert/Markus,melneubert/Markus,MarkUsProject/Markus,david-yz-liu/Markus,benjaminvialle/Markus,ealonas/Markus,melneubert/Markus,binuri/Markus,reidka/Markus,finnergizer/Markus,wkwan/Markus,WilsonChiang/Markus,binuri/Markus,arkon/Markus