This is on only one of my characters. Cannot click on any caches in ZM. There is no gear to click to open and start the puzzles. I have disabled all of my add-ons and reloaded. This did not fix the problem. The character is my priest, Mendi on Blackhand.
I don’t understand why this is happening on only one of my characters while other characters can open with no problem.
I’d first try a proper reset, Mendi. That is more than disabling and/or reloading.
Resetting the WoW User Interface - Blizzard Support (battle.net)
Has this character just started ZM. You have to do a bit of the campaign to be able to interact with the puzzle chests. At least it was like thar for me.
Like that! I’m not a pirate.
Thanks. I have done 3/7 on his character, and can do other world quests that aren’t puzzle solving related.
Does your robo friend have energy? I’ve never had mine run out so not sure what error it would give, but you need at least 2 energy to do the puzzles.
Edit to add: if you’ve been using a lot of combat abilities, interacting with coreless stuffs, etc, you could quickly run out of energy and not realize it.
You need to research Cachial Understanding in the Cypher system to be able to interact with the puzzle chests. I’m guessing you unlocked it on your other characters already, which is why you can do it on those and not your priest.
I am having the same problem on my Mage right now. Did you get the problem resolved? Just like you, all my other toons are able to interact with the puzzles except the one. If there is anything you can do to help, I would appreciate it.
On the affected character, have you completed Cachial Training in Firim’s Hideout?
Which one, Patti? You have a few Mages. 
It looks like you have completed “The Way Forward” on all of your level 60 Mages, so you should have access. Make sure you have completed the Cachial Understanding on the Cypher Console.
yes I have
It’s mage Zalda, and yes I have completed cachial understanding.
It’s not fixed… =( I guess I will have to try resetting the wow user interface.
Sorry, Patti, I had assumed you already had. It’s the first step we recommended in this thread. Please let us know if you continue to have an issue.
Just to update. I was able to check the character, and it doesn’t appear that you have completed Cachial Understanding on Zalda.
The option for Cachial Understanding, the one that is highlighted green in that first column and currently has the option to research it. 
Thank you so much! I didn’t look close, and thought that it was done. I was ready to put this toon on the back burner. Thanks again! Problem solved.