From what i can gather, it's caused by an outfit unlock that cannot be found, open the "profile.json" in your .toa-data folder with a text editor, scroll to the bottom and see if something's wrong.
It should look something like this if it's normal (i just used notepad):
View attachment 1390761
It seems i accidentally cropped out the last line by half, but then again i'm too lazy to fix that image so the last line should only have "}" without quotes.
And yes, i do not know if you can unlock "schoolgirl" and "lewd schoolgirl" outfits through ingame means, i just edited them there and it works.