Guys, I had this problem for several days and after trying EVERYTHING you could imagine, it was aways simple.
Some people already know, but the ones who don`t, here is the solution.
I had a steam profile with lots of different stuff for it to look good. I used some diff emojis and characters in the whole profile, but you CAN`T have that. If you have ANYTHING different from the usual keyboard in your profile, take it out. IT WILL WORK.
PS: Even the real name can not have something different.
PS2: If it doesnt work, reset your UID to numbers only, it should work.
PS3: If still not solved, send me a msg and I will figure it out for you.