Stupid miss click and canI fix this?

[Stefmon]

I was looking at my ranked characters at one point and then wanted to go back a page. Instead of pressing esc I pressed a button to the right. It said export to open. I was in a rush and clicked it thinking it would send me to the open page. Then I realised it removed ALL my Open and singleplayer characters and replaced them with my 1 ranked character. This is annoing. Can I reverse this and why is it not made more clear what the button does!?

[Ûvatha]

your local character are stored in:

DunDefHeroes.dun
DunDefHeroes.dun.bak

the files can be found in ...\Steam\steamapps\common\dungeon defenders\Binaries\Win32
If you haven't made a backup yourself it can't be restored.