I can't learn skills or professions

I started a new character on an old account that I rarely used and while I was leveling up every time I had a level to learn new skills and went to the instructor, the skill disappeared, as it looks when it is already learned. Being level 10 I have not been able to learn new skills or higher ranks; this also happens with professions, it does not let me learn primary or secondary ones. In this account I have 3 other characters and they cannot learn new professions or recipes either.

Attached SS link https://imgur.com/gallery/bug-zWHmUUC

P.S. When I use another account, this one does not have that problem, so I tried deleting the "WTF" and "Cache" folders as a GM recommended me by ticket, but the problem persisted the same.

there is 2 possibilities , either you have an addon that is keeping your UI bugged (disable all addons and try )
or your game files got corrupted (download fresh client).

Check the trainer window, there is a "filter" dropdown, make sure you haven't disabled anything.

oh my...
thanks bro, that was the problem
(huge) :D