So you're playing Pokemon Black/White and you try and visit your PC box, only to encounter...
the Blue Error Screen! (duh duh duh *dramatic reverb*)
What causes the Blue Error Screen?
The blue error screen is the result of the game encountering data that has somehow been corrupted. This corrupted data can't be read and causes the game to crash. There could be several different culprits, but the one I've seen most often (and the focus of this guide) is incorrect or improperly used AR codes for WonderCard Pokemon.
In the specific case of the WonderCard codes, the failed code generates corrupted data in two of your PC boxes: 6 and 7.
Corrupted data in my PC boxes? Does that mean all my Pokemon are gone?!
If the issue is the result of failed WonderCard codes, the answer is NO. From what I have seen, it is only the EMPTY SPACES in those two boxes that get corrupted, not the Pokemon themselves. The Pokemon are perfectly fine and can even be rescued if you have the means.
So, how do I fix it?
What you need to do is overwrite the corrupted data in the empty spaces of box 6 and 7. You can accomplish this by either manually adding Pokemon to those empty spaces (Methods 1 and 3), or deleting ALL the data from the boxes (Method 2).
1. NDS Backup Adapter Plus/R4 Save Dongle + Pokegen
This Method is recommended for those who want to save the Pokemon in the affected boxes and don't mind purchasing a very handy device to accomplish it.
Required Hardware: