I saw a post similar to this from a year ago, but my case differed from the one described.
I recently found that robots I've been exporting aren't in the robot designs folder. The only robots there are a few made by the player who provided the download I used. The older thread said to go via C:/Users/Family/AppData/Local/VirtualStore/Infogrames/Robot Arena 2/Robot Designs, but the virtualstore folder is completely empty for me (yes, I have enabled the display of hidden files).
Exporting works fine within the game, as I'm able to import all the bots again as normal.
I have one other copy of the game installed, which came bundled with my download of the robot wars mod. However, the designs folder of this version contains only the robots I uploaded from the modded game, so the vanilla bots haven't gone there by mistake.
It's unclear how long I've had this problem, as I've never tried to look in the designs folder before.
Any help is appreciated.