I Authentication problem on my phone it's a Android and I don't know how to solve it

[Talented Trokon]

I tried putting my wifi on and it turn on but it keep on saying Authentication problem I don't know how to fix it

 

[Phillip Corcoran]

Authentication issues are often caused by the user entering the wrong wireless key - - for example you enter uppercase letter when it should be lowercase, or vice-versa. Or you mistake letter 'b' for a 6.

Check the actual wireless key on your router and make sure to enter exactly the same key on your phone.