I'm getting the same bug on my end.
I load my save, it tells me about the new feature, then gives me an error when I press enter.
My save isn't being modified, because this happens each and everytime I try and load my save.
I've made a backup of my save so I can test what someone else tried with changing the save number.
I tried that, and it does load the save after changing the recorded slot number, but this appears to bypass whatever conversion is supposed to take place, because the game is showing that I have no clear records for any of the modes except wolf, which is what I'm currently on, but I checked my collection items, and I do indeed have at least 1 clear medal for all modes up to and includeing wolf.
Maybe this can be fixed soon?
Good thing I made a backup...
Oh, and this bug happens on my older saves to, so it's either something to do with the message that shows up when a new save is loaded after the 1.9.2 update, or its the conversion process that's bugged.
I aslo tested making a brand-new save file, and no bug happens.
While going to delete the test save I noticed that it was about 141 k in size while all my older saves are somewhere in the 78 to 81 k range.
Maybe all that extra space is for the new clear flags?
Later!