Up until a short while ago we could load worlds when we did not have all the eps the creator had installed - but a few weeks back those rules changed and we now have to have all eps the user had installed when they made the world - even though no epo stuff was in the world... or the world crashes as you described if it loads at all. In most cases people are reporting the worlds crash at the loading screen - so I have to wonder if perhaps Magic Dancer had an ep installed in her game when she last saved this world you may not have.
Also it might be a problem depending on which version you used - if you used the version with out even the empty lots, the World Editor that allowed us to add lots is basically borked and has been borked for a long time - but with each new ep and update it gets worse. it is highly possible if the crash occurs when you are trying to add lots the World Editor has just been totally decimated by the newest patches. So it all depends on where the problem is happening.
Also if you use mods and CC - it may be as simple as your latest update may be the culprit - for no rythme or reason we can figure - some worlds newly being installed may crash also as you describe of some of your content is already corrupted or bad due to a new patch - where other world will be find - for at least a while. Eventually bad CC or mods will claim those as well - it just seems some worlds are more affected sooner than others.
So trying to pin point you particular problem depends on a lot of different things - but I can assure you this world still work fine as usual - I have all eps and sps, all updates, and zero mods or CC. I also make sure my game is always up to date and all tools and aps the game needs to function properly are always up to date as well - which is Origin, adobe flashplayer, the store updates and game updates,Java, and my video cards drivers. I also keep my Operating system updated (weekly) and make sure the inside of my computer case is cleaned at least every two-three months.
Hope something there helps you.