I have run into a strange problem with PokeGen. I'm pretty sure its with PokeGen because I've meticulously ruled out everything else. Here's what is happening:
It has been a month since I last used any save state editors for a Pokemon game, including PokeGen. The last time I did so, I didn't have any problems. Then, yesterday, I used my NDS Adaptor Plus to load save files from my SoulSilver and Platinum versions. I then created a copy of each of those saves to use for a little editing (I always keep a copy of the latest save that was known to work without any issues). I proceeded to edit a few things in PokeGen. In the Platinum save, I duplicated a Carvanha that was in one of my PC Boxes, and placed the duplicate into another box. On SoulSilver, I duplicated a Happiny from one box to another, as well as duplicating a shiny Misdreavus that I was lucky enough to have caught in the Safari Zone. My intention was to evolve the Happiny with an Oval Stone, and to trade the Misdreavus to Platinum in exchange for the Carvanha I had duplicated in that game.
Here's where things get weird: I transferred the edited saves back to the proper game cards (which are retail versions bought brand new in North America, not R4 cards or something like that) and then booted the games, SoulSilver in my DS Lite and Platinum in my 3DS. They started up fine, with no problems whatsoever. I then moved the aforementioned pokemon from their respective PC Boxes into each game's party, and proceeded to enter the Union Room. However, the moment I walked one character (SoulSilver's) over to the Platinum character and pressed "A" to talk to him, both games displayed a blue screen that read something like this: (SoulSilver) "A communication error has occurred. Press A to return to the title screen." The message for Platinum was longer, but essentially said the same thing, except that it kicked me back to the Union Room instead of the title screen.
Needless to say, since I've never had any problem like this before with save state editors, I initially suspected the problem lay with the 3DS. So, I shut off both games, and moved Platinum over to my brother's DS Lite. I repeated the trade attempt, only to get the same error message at the exact same point in the process. After that, I began to suspect a PokeGen problem. So I turned off both games, put them back in the NDS Adaptor Plus, and transferred the unedited game saves I had made at the beginning of this whole process. Then I put each game in a DS Lite and tried to trade once more.
This time, I didn't get the error. I was somewhat relieved, but also puzzled. So I created new copies of my latest working saves, and edited them again with PokeGen, this time being careful not to accidentally click or change anything other than what I wanted to change. I put the games back in the systems, and entered the Union Room a third time, and as soon as I pressed "A" on the other character, I received the exact same error as before.
This made me suspect a problem with PokeGen even more, because the error didn't occur when I used game saves that hadn't been edited within the last month or so, and it did occur when I used game saves that had been edited that same day. So, once again, I restored the known working game saves to their proper versions, and then proceeded to create two new copies of them, this time with Pokesav. I performed the very same edits as I had with PokeGen, then saved my work, transferred the edited saves to the game cards, and entered the Union Room for fourth time.
This time, I was able to trade with no problems at all. Needless to say, I'm thoroughly confused. I hope this bug report will help me fix this problem, because I've come to prefer working in PokeGen instead of Pokesav, especially for Black and White, because my BW Pokesav doesn't have English names for Pokemon, items, places, etc.
Anyway, here is some additional info to help figure this out.
My version of PokeGen: 3.0.5
Operating System: Windows XP Pro with all the latest updates and working, up-to-date antivirus software
Hardware: Late 2007 Apple Macbook (dual-booting Windows via Apple's Boot Camp)
Also, I am including the relevant save files so you can take a look at them:
Here's a list of which save file is which:
These first two files are the ones that were simply a backup of Platinum and SoulSilver with no edits at all. They are known to cause no problems.
Pokemon Platinum JMA 06-16-2012 01.sav
Pokemon SoulSilver JMA 06-16-2012 01.sav
This second set of files are the ones edited in Pokegen that were causing the communication error in the Union Room.
Pokemon Platinum JMA 06-16-2012 01 Edit Pokegen.sav
Pokemon SoulSilver JMA 06-16-2012 01 Edit Pokegen.sav
This last set of files are the ones that were edited in Pokesav and didn't cause any problems either.
Pokemon Platinum JMA 06-16-2012 01 Edit Pokesav.sav
Pokemon SoulSilver JMA 06-16-2012 01 Edit Pokesav.sav
Pokemon Platinum .sav
Pokemon Platinum .sav
Pokemon Platinum .sav