I opened up Minecraft and began to load my world (which I've put around 30 hours into, me and a few of my friends) but before it can open the "software was closed because an error occurred" message appears. I've checked other worlds and they're fine, it's just the one. I tried copying the world and opening that up but the message still appears. 

Luckily (if you can call it that), I have been having a LOT of issues with Minecraft for the Switch, none of which I've had on other versions. I made a copy of the world yesterday, so I only lost a few hours of progress. Needless to say, I am very disappointed in the quality of the Switch port of Minecraft, I just picked it up last week. Online multiplayer is atrocious, but it seems the devs are working on that one already. It seems there's no hope for that save file, but it is necessary that this gets fixed, users should be able to rely on their save files without making a backup every single time they log off.