In case you run out of disk space during installation or update for Fortnite on console, there are a couple of things that you can try and resolve this. To begin with, you can try clearing the cache for your console type by following the steps in our official articles for each console below:
How do I clear my PlayStation cache?
How do I clear my Xbox Series S|X cache?
How do I clear my Nintendo Switch cache?
You can also try deleting any unused or unwanted Apps and Games in order to free up the required space for update. And if that doesn't work, the best thing you could do would be to reach out to our colleagues from the respective platform's support team, as they'll be better suited to find out what might be causing the problem and assist you in resolving it. You can find the official support links for all platforms in the links below:
PlayStation Support