Ok. Long story short : now it works, but I've no idea why. What I did :
- Create a complete backup of my X3TC/addon directory
- Try, one by one, to disable the scripts that could conflict. Considering many of the stuff I had did not show up in the plugin manager, it was not en easy task. And I couldn't even find the conflicting script.
- Out of despair, I made a list of the mods I knew I was using, and completely uninstalled X3TC + X3TC/AP with steam, and reinstalled it back
- Re-downloading every single mod I was using. Some of them couldn't be found anymore, or were outdated, and not working, like Economy and supply Trader
- Since I really wanted to use these now not working mods, I restored the backup I made in step 1
- ... and now, everything is working... no idea why
But seriously, I'm afraid one day it will go down and I won't be able to miraculously trick my way back,
@moderators : I'm not quite sure I can actually ask the following question. If I can't, I'll just remove this part from the post.
So... is it possible that somebody just zips his/her entire X3TC/addon directory and either uploads it by SFTP to a server I will provide, or just make it availlable to download with another online solution ?