Even though we are signed in to Nintendo on line play and our Microsoft account, access to marketplace is sometimes not available. Sometimes if we  open a world then save and quit,  then go back to the entry screen, the marketplace button becomes live again. 

If we do finally manage to get into marketplace, it crashes while trying to download the two dlc packs be have purchased (minions and SpongeBob). When this happens, we have to restart the software. 

so far we have tried restarting numerous times. We have signed out and signed back in to accounts. I have restarted my broadband router.  Nothing has changed and access is on and off and downloads are still crashing.