-Before it hapenned: I usually use the launcher even to come to the website, so I opened it and came to the login page of the client. The client started updating so I've let it go. Then again the client closed to Blizz Downloader, everything fine the patch dowloaded, no problem. The issue started when I tryied to reopen the Launcher, it doesn't work and the message above appears.
-What I've already did to try to fix it: I deletedd my cache,WTF and UI even if I don't think it can affect the Launcher at all. I went to see my firewall, in case it would have blocked a file or something, but no, I had set it so Blizz can do anything they want in my computer, no problem there.
-What I'll try after posting this: I'm gonna try to delete manually the new patch file, and download it again. I'll update this tread as needed.
*English isn't my first speaking language, so there WILL be mistakes in this message, I know it and I'm sorry for the lack of understanding it may bring. If needed, I'll try to explain differently.*