I have bought Chi Burn veno morai skill for 350 millions at one of the catshops. I went to learn it, and a few minutes later I've noticed that the book is still in my inventory and that the skill has been learned (I even tested, it did work). Although, I had 1 spot in my inventory empty (It was among the full spots, and I sort my inventory frequently). So, I was thinking that I somehow had 2 books instead of one, but I don't recall buying one before today, and I really wanted that skill to forget I bought it (I haven't gotten wasted lately, so don't count on that). Thinking further, I came to conclusion that empty spot could've been from ten million big notes which I spent on buying the book. If that is true, I think this is the duplicate glitch or something, because the book I bought couldn't be linked in world chat, only showed up as empty message that could've been sent. So, I would like this checked out because people could easily exploit this glitch.
Thanks in advance. I can provide screenshots if needed.