My Trial Of Ballance Code Wont Work

Did you piece together a code from all 4 trials?  You have to make a master code.

This video (not mine - just searched and found it).. shows what I mean:

It was recently brought to our attention that, while the codes are different for every player, it turns out that the order in which you press the plates to start a fight with a gnome king is actually the same for every player.

https://answers.ea.com/t5/Game-Information/Trials-of-gnomus-master-code/m-p/7940664#M34582

In that link is a master code for starting the rainbow king battle.  If your code for the trial of balance is not working, I suggest you watch a video of someone doing that trial including the boss fight, and noting the order in which they press the plates to start the gnome boss fight.

nota bene - I'm talking about the order of the plates on the ground, NOT the symbols on them.  The symbols will be jumbled for every player.  Also note, you cannot begin a boss battle before you have actually competed the trial.  Likewise, you cannot start the rainbow king battle until all four trials have been completed.