Hello, I know it's been a month but I figured I'd post my solution to the same error message and inability to load my game.
- Open up a save folder in elona\save that is NOT your corrupted save folder. Make a new game and save if you need to.
- Copy the gdata.s1 file from the uncorrupted save folder to the save folder you need to fix.
Load the game, it will say "could not load map" and, at least for me, popped me to My Home in the upper left corner.
According to the elosnack wiki page, the gdata.s1 file contains your current map location among other things (times wished from a fountain, whether or not you've gotten god gifts, your current/max cargo weights, etc.) so if you take this file from a new game those will all be set to default. Check the page on this wiki for more info.
To possibly verify we have the same bug, open up your corrupt save folder in elosnack and if the table labled Int32Editor (starts with Deepest Floor variable) has a bunch of 0s under the Value column, then that is at least one of your problems. Good luck!