Hacking cia issue with Gateway (and extra question for 3dz conversion)

[Aglae Pheryl]

Hi,

I have a few cia that I installed on the CFW of the O3DS (we're using Gateway).
I recently tried to install Game & Watch Vermin using Title Manager (Big Blue Box).

The install seem to work as usual but when trying to launch the game, all we get is a black screen and we have to force the console to power off and restart.

Should I edit these CIA files somehow?

BTW, when converting 3ds to 3dz using Gateway ROM Patcher1.2, I'm not sure I am doing what I should. Here's what I do (please tell me if I screw up somewhere):
1. open the 3ds file (load rom)

2. import header from file (using a dump of one of my own carts). Often getting a message here that there's some kind of issue and that the app can provide a better chain that I

3. change part of the chip ID (the first 10 digits) with the info from the nfo and finally apply changes.

Thanks